WORTS CONFERENCE ON SURVIVAL AND EMERGENCY RATIONS CONFERENCE iM ON SURVIVAL AND EMERGENCY RATIONS Held at the Knickerbocker Hotel, Chicago 5 September 1947 RESEARCH AND DEVELOPMENT BRANCH Office of the Quartermaster General QUARTERMASTER FOOD & CONTAINER INSTITUTE FOR THE ARMED FORCES Chicago 9, Illinois GREETINGS TO THE CONFERENCE Th 6 problem of survival where only minimum food and water are available poses problems to science and technology, the answers to which are fundamentally similar whether the emergency be on icebergs, life rafts, or the ground; whether it be occasioned by national emer- gency or disaster. In recent months, definite progress has been made in the formu- lation of a satisfactory Survival Ration. This, in itself, is an accom- plishment both tangible and significant. It is, however, additionally gratifying to know that the investigations involved have uncovered im- portant findings in medicine, physiology, and food technology. I am, therefore, doubly pleased to greet this conference. I extend best wishes for further progress, and I urge everyone concerned to con- tinue to devote his best effort in these, the final stages of this under- taking. The development of a satisfactory Survival Ration is indeed an important project, for the preservation of life is not only instinctive to man, it is also of fundamental importance for successful military operations. THOMAS B. LARKIN Major General Quartermaster General of the Army I CONFERENCE ON SURVIVAL AND EMERGENCY RATIONS (MORNING SESSION) Research Aspects of Survival and Emergency Rations CHAIRMAN - Dr. George H. Berryman 1. Welcoming Address. 2. Brief Discussion of Accomplishments of Food Research Program. 3. Background of Survival Ration. 4. Significant Contributions to the Survival and Emergency Problem. 5. Utilization of Food Proteins 6. Food Acceptance Test on Food Bars. Colonel Charles S. Lawrence, QM Food & Container Institute for the Armed Forces, Chicago, Illinois. Mr. George Gelman, QM Food & Container Institute for the Armed Forces, Chicago, Illinois. Dr. George H. Berryman, QM Food & Con- tainer Institute for the Armed Forces, Chicago, Illinois. Dr. C. G. King, Scientific Director, The Nutrition Foundation, New York City, New York. Dr. Pearl Swanson, lowa State College, Ames, lowa. Dr. W. Franklin Dove, QM Food & Container Institute for the Armed Forces, Chicago, Illinois. Intermission 7. Recent Findings on Project “The Utilization of Proteins and Amino Acids”. 8. Recent Findings on Project “Protein Metabolism Studies on Reduced Caloric and Water Intake”. Dr. J. B. Allison, Rutgers University, New Brunswick, N. J. Dr. David Schwimmer, New York Medical College, Welfare Island, New York. Luncheon (AFTERNOON SESSION) Developmental Aspects of Survival and Emergency Rations CHAIRMAN - Dr. Howard D. Lightbody 9. Discussion of Survival Ration and Emergency Food Items Recently Developed. 10. Report of Food Acceptance Test on Food Food Bars. Dr. Harry L. Fevold, QM Food & Container Institute for the Armed Forces, Chicago, Illinois. Mr. J. E. P. Libby, QM Food & Container Institute for the Armed Forces, Chicago, Illinois. II 11. Results of Recent Studies on the Air- Borne Life Raft Ration. 12. General and Clinical Aspects of the Assessment of Nutritional and Meta- bolic Condition in the Field. Capt. James L. D. Roth, M. C. Aero-Medical Laboratory, Wright Field, Dayton, Ohio. Dr. Robert E. Johnson, Director, Medical Nutrition Laboratory, Chicago, Illinois. Intermission 13. Round Table Critique and Suggestions for Future Work. Lt. Col. Manley C. Perry, Chief, Rations Planning Office, QM Food & Container Institute for the Armed Forces, Chicago, Illinois. The following participated in the discussion Dr. C. G. King, Sci. Dir. Nutrition Foundation. Colonel James C. Barta, Strategic Air Command. Colonel George F. Keenan, A.A.F. Liaison Office, OQMG. Colonel Henry Dittman, Headquarters, Army Air Force. Lieutenant Colonel JohnE. Crowley, Office of the Air Quartermaster. Dr. True Robinson, Aeromedical Laboratory. Lieutenant Colonel Ralph H. Wiltamuth, Headquarters, Army Ground Forces. Lieutenant Colonel Richard K. Boyd, Army Ground Forces, Board No. 3. Lieutenant Colonel Richard L. Lewis, Research & Development Br., OQMG. Lieutenant Commander Richard T, Power, USN Liaison Officer, QMF&CI. Lieutenant John C. Herron, Bureau of Supply and Accounts, U. S. Navy. Major Fenwich W. Holmes, U. S. Marine Corps. Lieutenant Commander W. J. Conely, Coast Guard. Mr. Emory W. Thurston, Emory W. Thurston Laboratories, Los Angeles. 14. Adjournment Colonel Charles S. Lawrence (E VE NING SE SSION) Research Problems Related to Survival and Emergency Rations CHAIRMAN - Dr. George H. Berryman 15. Round Table Discussion The following were in attendance: Dr. James B. Allison Dr. H. S. Belding Dr. Sadie Brenner Dr. Paul R. Cannon Dr, H. J. Deuel Dr. H. L. Fevold Mr. George Gelman Dr. Austin Henschel Dr. A. Stuart Hunter Dr. Robert E. Johnson Dr. O. G. King Dr. Howard D. Lightbody Dr. Daniel Mslnick Dr. Herbert Pollack Dr. True W. Robinson Capt. James Roth, MC Dr. David Schwimmer Dr. Pearl Swanson CONFERENCE ON SURVIVAL AND EMERGENCY RATIONS (MORNING SESSION) Research Aspects of Survival and Emergency Rations DR. BERRYMAN: We shall begin this morning’s session with greetings to the conference from Col. Law- rence, Commanding Officer of the Quartermaster Food and Container Institute for the Armed Forces. Colonel Lawrence I COL. LAWRENCE: Ladies and gentlemen, having to face such an august group as this leaves me almost speechless. I suppose that I should have a carefully prepared and memorized address, but I learned rather early in life,that it is sometimes a mistake to spend too much time in preparing and memorizing talks. In my young and more irresponsible days I was studying in one of the agricultural schools and had occasion to prepare a talk on the care and breeding of swine. I spent days and nights preparing my speech and memorizing it. At the same time I was going with a very beautiful girl, with gorgeous red hair and blue eyes. I was very much in love with the young lady. A few days before I was to deliver my talk on swine, I got her out in a rowboat and began to propose. I had been talking for about 15 minutes before I discovered I was talking about pigs insead of love. Right there I muffed my chance of marrying one of the richest and most productive oil fields in Oklahoma. I have never gone in for prepared addresses since. I would like to say the Food and Corltainer Institute of the Quartermaster Corps is happy to have such a group present for this conference. The problem of survival rations is one of the most urgent of the military feeding problems confronting the Armed Forces at the present time. Modern conflict extends beyond the military arm and involves in some instances large numbers of our civilian population. At one time survival rations were used for the Armed Forces only. Now we have to contemplate the use of survival rations for many thousands of the civilian population. For that reason the survival ration takes on increased importance. I am not an alarmist about the prospect of war in the immediate future, and we hope that we will never have armed conflict again, but I think it behooves us to pay attention to the old Chinese prophecy which reads, “Enjoy yourself; it is later than you think’’. I think that for our use we might say, “Prepare ourselves, it is later than we think”. May I say again that I want to welcome you on behalf of the Quartermaster Food and Con- tainer Institute. lam sure that great good will come from this conference on survival and emergency rations. DR. BERRYMAN: Thank you, Col. Lawrence. It gives me great pleasure to introduce the Technical Direc- tor of the Institute, Mr. George Gelman. MR. GELMAN: Mr. Chairman, officers, ladies and gentlemen, it is very gratifying indeed to have assem- bled in one room the Armed Forces, university scientists, and industry scientists to share with us in a discussion of the survival and emergency type ration. This ration, perhaps more than any other, can be truthfully said to be scientifically designed and solidly based on funda- mental studies of physiology and nutrition. The speakers who are to follow will give you the evidence and facts upon which the emer- gency ration in its present developmental stage is founded. I would like in a collateral way to indicate that the research program of the Institute in cooperation with a number of university research departments and Government research agencies has made it possible for us to have information that is helpful in estimating the shelf life or the stability of the ration that is to be developed, and which, when confirmed by actual storage and field studies, will in considerable degree measure the acceptability of that ration. Such a measure has never been entirely possible in the past. It is not by any means perfect now, but it is far enough along for us to 1 place reliance on the background information which has been developed in the universities and in our laboratory. Our program of outside research is centered largely in 3 categories: (1) research in methods of preventing deterioration, whether they be chemical, microbiological, or physical; (2) research in the field of food acceptance, which embraces 3 general categories of studies -- food habit or psychosociological studies, psychophysiological studies, which attempt to as- certain the nature of the mechanisms controlling food intake, and psychophysical studies, which provide information we need to obtain a screening of acceptability in the laboratory, using human beings as research tools to provide information that we cannot measure chemi- cally or physically by the usual laboratory methods; and in addition, of course, (3) the nutri- tion program which has made an impact on this particular problem of survival, and about which you will hear more from Dr. Swanson, Dr. Allison, Dr. Schwimmer, and Dr. Berryman, and in the afternoon from Capt. Roth, Dr. Fevold, and others. We are fortunate in having Dr. Mitchell’s contribution a tremendous survey he is undertaking on nutrition and resistance to climatic stress. Last week when he was visiting the laboratory, Dr. Mitchell told me that 2,000 abstracts covering his report on that problem will soon be available. There have been numerous contributions from many distinguished persons in this country to our general problem of Army ration nutrition, and it all has a bearing on this specific problem of survival rations. I hope some time today we will have a chart brought up to this roomwhlch will illustrate diagrammatically the nature and scope of this program. In about 2 months we hope to mail to you a detailed analysis of our entire research program described by projects and phases. We have had a somewhat late start. I would like to make my contribution by stopping now so that'you may have the full time of the other speakers. Our next speaker will be Dr. Berryman. DR. BERRYMAN: Background of Survival Ration* In order to survive until rescue, the castaway must reduce to a minimum the adverse physiologic effects due to environment, so that he does not die from exposure; he must con- quer fear; he must either find potable water, or at least keep his body water losses to a minimum; he must replace salt losses; and finally, for a period of long survival, he must have access to food. These five factors are listed in a sequence approximating relative im- portance; let us examine them in greater detail. Environmental protection is of first importance. Occasionally, the environment may be irremediable, as for example, when a flier is ditched into very cold waters such as those around the Aleutians. Here, death from exposure is reputed to occur in less than an hour. In'the majority of circumstances, however, certain steps can be taken to cope with environ- ment. Thus, in the Arctic, provided the survivor is adequately clothed against freezing, it will be of further aid to try to avoid sweating and to favor ventilation by opening clothing at the neck and wrists and loosening the waist. The vascular circulation should be aided by wearing clothing loosely. Dry grass or kapok from airplane cushions makes excellent insula- tion for the feet. Clothing can be kept as dry as possible to deter freezing. Shelter can be improvised by building “bough dens” reinforced with snow, or snow caves, and by the judi- cious use of snow banks. In the summer, sunburn can be guarded against, and sun glasses may be improvised to prevent snow-blindness. Appropriate steps can also be taken in the tropics. Staying in the shade and other measures sparing of body water are of paramount importance, for obviously here the prob- lem of water and salt is critical. The need for avoiding mosquitoes is more or less a well known precaution, as well as the use of malaria-suppressant drugs. Shelter from both sun and rain is usually facilitated by the profusion of trees and other vegetation. Measures to avoid ticks, leeches, spiders, scorpions, and the like must also be taken. Protection against poisonous and irritating plants is also necessary. 1 For bibliography on survival rations see Appendix A. 2 Control of one’s fear, or conversely, bravado, is considered by many to be of almost equal importance with the necessity for controlling environmental disadvantages. Many a castaway on a raft has hastened the end by resorting to large quantities of sea water as a means of assuaging thirst. Many a castaway on land has hastened the end by an unjudicious decision to travel in the height of the sun. The continuing desire to live may be listed as one personal trait that stands out in importance above others. If, then, it be granted - as it is universally - that food may favorably influence the kind of decision which the castaway makes, and aids morale and courage, it follows that a survival ration may be a significant factor in saving life. The need for water is not immediate, but it may arise early in the course of survival, depending on the environmental temperature and the amount of physical exercise. Table 1, taken from Army Air Forces Manual 64-0-1, illustrates this point. While certain measures can be taken to conserve water, the minimum daily quantity required for the average person in a temperate environment has been estimated by Gamble to be about 700 cc. This is, of course, considerably less than the amount normally consumed, which may average about 2.5 liters or more, depending on work and temperature. An interesting and important point about the body’s requirement for water is that it may be profoundly influenced by the kind and amount of food that is available. Protein increases the requirement, while carbohydrate and fat decrease it. The need for salt is closely related to that of water. The Food and Nutrition Board, National Research Council, lists five grams daily as being a liberal allowance, but further designates the average normal intake of salt to be as high as 10-15 grams per day, when water intake is not more than 4 liters. For every liter of intake above four, an additional gram of salt is recommended. It would seem, however, that once adjusted to the environ- ment, the average person may not need as much as this, for the salt concentration of sweat is then considerably lower. Basically, the needs are to replenish the salt lost by the body. TABLE 1 DESERT WATER DATA TABLE Maximum Daytime Tempera- tures In Shade Entire Water Supply Per Man Approximate Survival Days Approximate Survival Days (When Resting In Shade At All Times) (When Traveling Only At Night & Resting In Shade By Day. Also Distance You Can Travel) VERY HOT .No water 2-5 1-3 days 20 miles 100° F. 1 quart 2-5 1/2 2-3 1/2 days 20 miles & above 2 quarts 2-6 2-3 1/2 days 25 miles 4 quarts 2 1/2-7 2 1/2-4 days 30 miles moderately No water 5-9 3-7 days 20-40 miles HOT 1 quart 5 1/2-10 3 1/2-7 1/2 20-45 miles 800 - 100° F. 2 quarts 6-11 3 1/2-8 days 25-50 miles 4 quarts 7-13 4-9 days 30-60 miles COOL No water 9-10 7-8 days 40-60 miles Under 80° F. 1 quart 10-11 7 1/2-8 1/2 45-75 miles 2 quarts 11-12 8-9 days 55-100 miles 4 quarts 13-14 1/2 9 1/2-11 60-150 miles Adapted from: Army Air Forces Manual 64-0-1, “Survival”, June 1945. 3 It is a truism that the castaway rarely dies from starvation.* The specific physiologic need for food in a survival situation is not a critical one, although as mentioned above, the psychologic aspects of the problem probably make food quite important from the overall standpoint. Insofar as actual starvation and its attendant inanition are concerned, it is re- ported that the castaway on a raft can “survive without food, but with ample water, for twenty to thirty days or longer, provided he is not subjected to physical strain, ” This may be contrasted with average survival time without water, which probably does not exceed ten to fourteen days even under the most favorable circumstances. At sea, the maximum re- corded period of survival without water is eleven days and it can be considerably less than that in some individuals. It does not seem that all the nutritive components of food are needed in the same de- gree for survival. For preventing physical deterioration, calories and protein rate highest. (There is, however, a definite limit on the amount of protein that should be eaten, for the metabolic end products Increase obligatory urine volume). Except for sodium, (as salt), minerals are not a critical factor. For the relatively short periods ordinarily involved in survival, there is no evidence from the physiologic standpoint justifying any concern for vitamins, provided the castaway was not originally in a depleted state.** Vitamin supple- ments may, on the other hand, exert a favorable psychologic effect, if they can fit into the ration conveniently. Having rapidly reviewed the hierarchy of factors involved in survival, let us examine more closely the components of water balance, as a preliminary to considering the types of food suitable for a survival ration. The components of water exchange when there is no food intake are indicated in Figure 1. There are two items of expenditure; (1) water which leaves the body as water vapor by way of the lungs and skin - the so-called insensible loss, and (2) water removed by the kidneys. This total outgo is only in small part covered by water produced by oxidation of protein, fat, and carbohydrate. In fasting, there is an additional source of water from the cellular breakdown of body substance, but this does not contribute to gengral dehydration. As Gamble states: “This is water which, under the circumstances imposed by fasting, is physiologically expendible/’ In fasting, this source of fluid, together with water of oxidation, aids in maintenance of homeostasis. It will be noted from the dia- gram that water drunk under guidance of the sensation of thirst usually provides a gensrous margin over obligatory expenditure, indicated by the broken line, and so leaves a large sur- plus to be removed in the urine. One exception to this occurs in extremely hot environment, however, where thirst may not be a dependable guide to water requirements. The larger component of the obligatory outgo of fluid is the insensible expenditure, and since this has a direct relationship to the metabolism of energy, it is apparent that at rest, it will be at a minimum. In the tropics, this is the basis for recommendations to avoid physical activity as much as possible, and to decrease the vaporization of body water as much as is compatible with maintaining body'temperature. Usually the castaway in the tropics intuitively talfes measures to decrease environmental warmth, and to substitute for the vaporization of body water other processes of heat removal. These measures are the following: (1) Stay in the shade. (Direct reduction of environmental temperature) (2) Increase the cooling effect of breeze by removal of clothing. (Promotion of convection) (3) When at sea, periodically immerse in the sea water. (Promotion of conduction) (4) Wet clothing with sea water. (Vaporization of sea water in place of body water) * Thus, in the Arctic, clothing, shelter and signalling devices, fuel and heat, water may be listed as taking precedence over food; in the tropics, environmental protection, salt and water play a more Im- portant direct role than food. ** This statement might possibly require modification If survival periods exceeded, say, three weeks. 4 WATER URINE Minimal Water Intake Minimal Urine Water DRUNK WATER Water of Oxidation Extra- Cellular BODY INSEN- SIBLE WATER WATER Intra- cellular *FIG. 1. WATER EXCHANGE DURING FASTING, WITH SURPLUS WATER INTAKE •Taken from: "The Water Requirement of Castaways" by James L. Gamble, Proc. Am. Philos. Society, Vol. 99, #3. 19W. An appreciation of the minimum water requirement can be gained by considering the concentrating power of the kidney. The total amount of metabolic solutes requiring excre- tion, divided by the maximum concentration that is ordinarily found to be within the capacity of the kidney (1.4 osmolar), provides a measure of the obligatory urine water. A specific example cited by Gamble illustrates the principle. A 24-hour collection of urine amounted to 1240 cc. having a freezing point depression of -1.19° C. An osmole of any solute lowers the freezing point of water by -1.86° C. Thus, * * milliosmols of total solutes requiring excretion; and s 566 cc, minimal urine volume, provided there is no impairment in kidney concentrating power. Now, it is important to note that the urinary volume can be even further decreased if the castaway eats a type of food sparing body protein. This is usually considered to be carbohydrate, although fat may exert a similar effect, which may, however, be complicated by the production of a concurrent ketosis. A specific example of the effect of carbohydrate can be cited, again taken from Gamble. Table 2 presents the essential data. It is seen that, when compared with the results found in fasting, feeding of 100 gm. of glucose has two effects upon water balance: (1) favorable - in that renal water is decreased, and (2) unfavorable - in that there is a decrease in the amount of body water arising from extracellular and intra- cellular sources. Since, however, the latter is less the former, the net result is a gain of 140 cc. of water to the individual, as well as a sparing of his bodily tissue. Thus, 100 cc. of water requirement for fasting can be replaced by glucose, and the incident benefits of glucose (tendency to avoid inanition and lassitude, and to maintain cheerfulness) are obtained. In addition, carbohydrate, when taken in sufficient quantity, prevents the characteristic Ke- tosis of starvation. Table 3 indicates the role that organic acids of ketosis may play. It is seen that the absence of these substances when glucose is given accounts for thirty-eight percent of the total reduction in solute output. Thus, both the anti-ketogenic effect of glucose and its pro- tein sparing effect reduce the solute output, and thereby conserve body water. There is yet another factor, although a slight one, involved in water balance. This pertains to water of oxidation. Table 4 indicates the relative amounts of water produced by 5 TABLE 2 EFFECT OF GLUCOSE ON WATER EXCHANGE Subject M. G. Minimal Urine Water cc. Available Body Water, cc. Fasting 521 100 gm. glucose 223 Reduction. . 298 Gain in water exchange 298-158= 140 cc. 518 360 Values average per 24 hrs. for 6-day periods omitting first day. Taken from: “The Water Requirement of Castaways” by James L. Gamble, Proc. Am. Philos. Society, Vol. 88, #3, 1944. TABLE 3 EFFECT OF GLUCOSE ON OUTPUT OF SOLUTES IN URINE Subject--M.G. Milliosmols per 24 Hrs. Total Solutes Organic Acids nh4 Org. Ac. + NH4 Fasting 784 133 86 219 100 gm. glucose 362 39 21 60 Reduction 422 94 + 65 = 159 159/422 0.38 Data from 6-day periods (omitting first day). Taken from: “The Water Requirement of Castaways” by James L. Gamble, Proc. Am. Philos. Society, Vol. 88, #3, 1944. TABLE 4 WATER OF OXIDATION FROM FOOD Substrate of oxidation H2O produced 1 gm. (gm.) Glucose Sucrose Starch or glycogen Fat Protein 0.600 0.579 0.556 1.071 0.396 the oxidation of 1 gram of carbohydrate, fat or protein. It will be noted that the water of oxidation of fat is high by comparison, but more importantly, that of protein is least - another reason why the level of protein consumed in the absence of water must be limited. In summary, the following points are salient for the conservation of the body water of the castaway: 6 (1) in isolation, where water supply is a problem, the type of food consumed may play an important role in prevention of rapid dehydration;- (2) the chief component of food adversely affecting water balance is protein, because its metabolic end products require water for excretion, and less important, its water of oxidation is less than that of carbohydrate or fat; (3) carbohydrate and fat exert a protein-sparing effect, and thus decrease the amount of obligatory urine; carbohydrate also aids in preventing ketosis, and is much less nauseating than are equal quantities of fat; (4) insensible loss of body water should be kept at a minimum by limiting activity and promoting cooling. Turning now to the application of these principles to the development of rations, it will be recalled that one of the early survival rations - the Life Raft Ration - was composed of 100 grams of pure carbohydrate in the form of Charms candy. On the basis of the foregoing, it is apparent that this ration was based on sound physiologic principles. The otter Survival or Emergency Ration, the D Bar, contained other nutrients that were surprisingly close in quantity to the amounts presently proposed, as we shall see. However, there were also several objections to these rations on acceptability grounds. Thus the candy ration was re- ported to cause sore mouths and to be unappetizing for any length of time exceeding a day or two. Candy is thirst provoking to many. The D Bar depressed appetite, caused gastroin- testinal upsets in some and, in general, was claimed to be thirst provoking because of the chocolate content. These rations were, therefore, not ideal; yet, in retrospect, they had several happy properties in relation to size, shape, stability, and caloric density. In addition, they could play, an important role in contributing to the morale of the subject. At this point, we might digress momentarily to state that to many, the psychologic problems of survival far outweigh the physiologic. This feeling about the relative unimportance of what (and if) one eats in survival circumstances is seen in such statements as “the best survival ration is a rapid rescue", and others of that nature. This line of thought might be pursued further, however. If food is to be provided for psychologic reasons primarily, there is still no reason why it should not also be physiologically sound and of such a nature as to conserve physical and mental efficiency. After rescue, overall recovery with return to duty, wound healing, etc., will proceed at a far faster rate when extreme depletion has been prevented. By all criteria, therefore, if a survival ration is to be made, it should not be planned oblivious of food values. In 1943 there occurred the most important technologic achievement of the war, as far as survival is concerned. This was the rendering of sea water potable by a desalination technique. A solar still was also developed. The upshot of these advances was that in many situations at sea, dehydration was no longer the factor completely Limiting the kind of food that could be used in survival. It was estimated that an average 800 cc. of water could be depended upon daily as the combined output from desalination Mt, solar still, and from rain- fall. This turn of events roused again the conviction that many had held previously; namely, that while survival rations must necessarily be high in calories and sparing of body water, they should nevertheless contain familiar and well-liked food items, should be less confec- tion-like, and furthermore, should contain as much protein as possible in the interests of preventing marked loss of body protein. The big question was -- how much protein could be incorporated for a water intake presumably averaging 800 cc. per day, and what source of protein would favor the attainment of nitrogen balance? This last factor involved the amino acid make-up of protein -- and this was a field only recently explored, insofar as the familiar human foods were concerned. As a means of obtaining the needed information, several re- search projects were established through the Committee on Food Research, Quartermaster Food & Container Institute for the Armed Forces. Within the past two years, valuable in- formation has been obtained, not only relating to these immediate problems, but also in the basic physiology of low-calorie, low-protein feeding. These will be discussed briefly. Early in the program of investigation, there emerged one finding that appears to be basic in feeding the small amounts of food characteristic of survival rations. Swanson, working at lowa State College, found that egg protein apparently conserved body protein in protein-depleted animals, and caused an unexpectedly marked reduction in the amount of urinary nitrogen excreted on a protein-free diet. This work was then repeated and verified 7 by Swanson, as well as by Allison and co-wohkers at Rutgers University, using rats and dogs respectively as test animals. Furthermore, this effect was similar to that obtaired when an equivalent amount of dietary nitrogen was supplied in the form of the ten essential amino acids. The effect seemed to be related to the high methionine content of egg protein, for the addition of dl-methionine to diets containing proteins other than egg resulted in greater nitrogen sparing. Here was an exciting possibility for use in survival ration planning. However, verifica- tion in human subjects was needed. This was undertaken initially by Schwimmer and co- workers at New York University. It was later investigated by R. M. Johnson and co-workers* at the University of Southern California, and also coincidently by Cox and co-workers at Washington University School of Medicine, St. Louis, and at New York University. The over- all results were strikingly similar, and served to point up the great, care needed in applying to humans results obtained by animal experimentation, even though the latter is a necessary and important forerunner. For in the human, no nitrogen-sparing effect due to added methionine was found such as that observed in rats and dogs. The conclusion was reached that a differ- ence in species requirement for methionine was responsible for the difference in results. At about the same time, additional work was begun on other phases of the low-protein, low-calorie intake problem by Schwimmer and associates. Comprehensive investigations upon several series of human volunteers undergoing twenty-eight dietary regimens were carried out. These investigations were based on the previous findings discussed above, and were designed to investigate several important questions that had arisen as a consequence. The resulting data, together with those originally obtained, form the basis for the present planning of the Survival ration. The immediate applicable findings** of the New York group were these: 1. Nitrogen sparing is absent in the 400-500 calorie range of feeding (level of standard Life Raft Ration). 2. Nitrogen utilization is optimal at 1500-1800 calories when 20 grams of protein (derived from dehydrated fermented egg white) are fed. When 40 grams are fed, a striking improvement in nitrogen balance occurs at all levels from 900 to 1800 calories, and the net amount of nitrogen retained by the body is greatest at the 40 gram protein intake level. 3. Urinary volumes are not increased when as much as 20 and 40 grams of protein are fed at 1500-1800 calories, averaging 30-60 cc. less than when no protein is ingested at 450 calories, and 115-145 cc. less than when 10 grams of protein are given at 450 calories. In addition, the superiority of egg white over certain other types of protein was again reported. This was significant, for it provided verification of the earlier findings in animals that were withheld from application to survival ration planning when the species difference in the methionine effect was uncovered. The findings of Schwimmer and co-workers showed very clearly that for short periods of time, when egg white was the sole source of protein, there was a marked reduction in nitrogen excretion*** as compared with the results obtained when lactalbumen (high ash content) or malted milk protein was used, or no protein at all. This same effect was obtained at both the 20 and 40 gram levels of protein intake. The basis for the apparently superior effect of egg protein over many other proteins is apparent from a tabulation of the amino acid content of egg white and whole egg versus certain other foods. See Table 5. [lt will be noted that the egg white and whole egg values per 100 grams exceed man’s average requirements Columns 1,2, and 3 while none of the other common proteins approach the egg in biologic value, considering all the component amino acids, with the prom- inent exception of SERUM PROTEIN. * Ondar the direction of Dr. H. J. Deuel. •♦•These findings were obtained over experimental periods of 5 days only, however. *** It Is recognized that to some, nitrogen-balance considerations may not be acceptable as a criterion for Survival feeding policy; 1.e., blood protein and hemoglobin regeneration may be equally valid criteria. 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 AMINO ACIDS MAN’S WHOLE AVERAGE EGG WHOLE EGG EGG SERUM LACTAL- MILK ZEIN RICIN PEANUT SOYBEAN WHEAT REQS.* WHITE EGG YOLK ALBUMEN PROTEINS CASEIN BUMIN COW FLOUR MEAL FLOUR gm. ARGININE 3.5 5.8 8.2 5.7+0.3 5.8+0.3 4.1+0.2 3.5+0.5 4.3 1.6+0.2 11.7 9.9 5.8 3.9 HISTIDINE 2.0 2.2 2.6 1.8+0.3 2.5+0.1 2.5+0.3 2.0+0.3 2.5 0.9+0.2 0.0 2.1 2.3 2.2 LYSINE 5.2 6.5 5.5 4.5+0.5 8.0+0.4 6.9+0.7 8.0+1.1 7.5 0.0 6 3.0 5.4 1.9 TYROSINE 3.9 4.8 5.3. 4.2+0.1 5.4+0.3 6.4+0.4 5.3+0.1 5.3 5.0+1.2 2.7 4.4 4.1 3.8 TRYPTOPHANE 1.1 1.6+0.2 1.6+0. 1.4+0.2 1.7+0.1 1.8+0.2 2.3+0.3 1.6 0.1 0.4 1.0 1.6 0.8 PHENYLALANINE 4.4 5.5 577 6 5.4~ 5.2+0.5 5.5 5.7 5.4+0.7 5.4 5.7 5.5 CYSTINE 3.8** 2.3+0.4 1.9 1.7+0.2 3.6+0.1 0.35+0.04 3.0+0.2 1.2 0.8+0.1 1.0 1.6 0.6+1.4 1.9 METHIONINE O 2-3 5.0+0.3 2.1 3.5+0.3 2.8+0.2 2.8 2.4 0.9 2.^ 3 SERINE 7.6 6-7 4.9 THREONINE 3.5 4.9 3-4 6.3 3.9+0.1 5.3 4.6 2.4 2.7 1.5 4.0 2.7 LEUCINE 9.1 19.0+2.1 9.4 18 12.1 15a 23.7f2.1 15aa 5.5 6.5 12.0+2.6 ISOLEUCINE 3.3 5.3+D.3 3 6.5 4.3+0.4 3.4 4.7 3.7+0.2 VALINE 3.8 4.4+0.6 6.8 6 7.0 4 2.4+0.9 2 4.0 4.2 3.4+0.5 GLUTAMIC ACID 16.3+0.2 22.8 35.6 19 ASPARTIC ACID 8.2+0.2 6.3 3.4 2 GLYCINE 2.5 1.9 0.5 0.0 5.6 7.2 ALANINE 7.4 5.6 0-1 9.9 PROLINE 4-5 8.2 9-12 4 HYDROXYPROLINE 0 2 1 0 APPROXIMATE PERCENTAGE OF AMINO ACIDS IN VARIOUS FOODS (BLOCK & BOLLING) TABLE 5. * Calculated ** Cystine plus Methionine a Leucine and Isoleuolne aa Includes Isoleucine 9 Using egg white and whole egg values as criteria, zein, ricin, peanut flour, soybean meal, and wheat flour would have marked amino acid deficiencies, quantitatively speaking, when used as the only source of protein. (NOTE: It is quite possible that if some of these proteins were used together in a ration, they would supplement each other to the extent of obviating the quan- titative deficiencies they have individually. Other important data were obtained from this series of investigations. It was found that the frequency of feeding (one feeding versus four versus twelve) had no statistically significant effect upon the sparing of nitrogen or upon urine volume. The principle of frequent feeding re- quires further investigation, however, because it is reported that in the Arctic an overall feel- ing of well-being occurs from eating more often, and also because of the general belief that more efficient utilization of food in the body is promoted by feeding a given amount of food in small quantities as compared with a single large quantity. Increase of caloric output did not appear to affect nitrogen balance or urine volume to any great extent. This finding, too, should be checked, for it is an important point. It may have a bearing on the situation in the Arctic where a greater amount of energy is needed, pre- sumably due to factors not encountered in warmer regions such as (1) need for maintaining body temperature; (2) direct effect of cold upon B.M.R. when shivering or its preceding muscu- lar tenseness occurs; (3) “hobbling” effect of Arctic clothing, which increases the caloric cost of any activity. It will be recalled that dietary protein at low levels of intake may or may not be used for tissue repair and replacement purposes depending on the fraction of the daily energy requirement that is supplied. Thus, in the Arctic, if a survival ration provides a smaller fraction of the daily energy requirement than was originally planned, the whole pur- pose of nitrogen sparing might be defeated. Another interesting and important point which has been raised by this same series of in- vestigations concerns the effect of fat upon the sparing of nitrogen. There is now some indica- tion that the same nitrogen-sparing effect found to occur in the 1500-1800 calorie range, can also occur at a lower calorie level, provided the fat content of the diet is increased at the ex- pense of the carbohydrate. This finding is at once both important and potentially dangerous. It is important in that the foot soldier under survival circumstances requires as compact and calorically high a ration as can be devised for him to carry conveniently, and in that it will permit the easier carrying of emergency food for longer periods of time, while presumably -inhibiting hunger. It is somewhat dangerous, however, in that the goal of high caloric density may be permitted to supersede that of highest palatability.* Any diet containing too much fat would not only be nauseating to most, but might also dispose towards a condition of ketosis and acidosis. Above all other considerations, however, there is every indication that such a ration would lack palatability - and paradoxical though it may seem, there is a considerable amount of evidence that the castaway will not “eat anything’ , even though starving. It is pertinent, now, to appraise where we stand in the actual development of a survival ration. On the basis of the previously described evidence that was obtained through a practical and intensive program of research coordinated and brought to overall fruition through the ef- forts of Dr. Samuel Lepkovsky, the indications now are that the nutritional characteristics of the Survival Ration should be as follows: a. Total caloric intake - 1800 calories per man per day. b. Proportions of carbohydrate, fat and protein - Protein -- 34-50 gms. per day (8-10% of calories) Fat 40-60 gms. per day (20-30% of calories) Carbohydrates -- 275-325 gms. per day (60-70% of calories) Vitamins and minerals --as provided in the natural food composition of the ration. c. Food composition - Protein sources of highest nutritional value; e.g., dehydrated whole egg or egg white, rice flour, dehydrated skimmed milk; fat sources must be those likely to undergo a minimum of deterioration; carbohydrates chiefly dextrin, soluble starches, and sucrose. * Then, too, It is desirable to supply as much of the dally caloric requirements as possible; therefore, many feel that additional fat should be considered from that standpoint, rather than only as a means of decreasing the size of the ration. 10 d. Highest order of acceptability - Palatable, edible under temperature extremes (-500 to +l2o° F.), non-thirst-provoklng (subjectively), swallowed easily with restricted free water supply (approximately 800 cc. per day), and should provide variety in form, color, flavor, and consistency. These are the requirements as set forth by Headquarters, Army Air Forces. It is highly doubtful that these same requirements can be used for other operations, particularly the foot soldier, for the size and weight requirements for an Air Force Emergency ration are very different from most others. (Ttere is the possibility that such a ration could be dropped by the Air Force to castaways in a wide range of circumstances.) On the basis of present know- ledge, a combination of food items embodying the characteristics listed above has been de- veloped by the combined efforts of the Quartermaster Food & Container Institute for the Armed Forces and the Aero-Medical Laboratory, It is felt by many, however, that consider- able improvement can yet be made in the acceptability of these food items which represent only the initial attempt at Incorporating into a ration the desired characteristics. In such ef- forts, one is brought face to face with the too frequently unappreciated difficulty of transpos- ing physiologic requirements into the palatable, familiar, easily-packaged, compact, stable food items that are required ultimately for use as a ration. It is gratifying to be able to state that considerable progress along this very line has been made by the Food Development Divi- sion of the Institute. Thgir most recently, developed food items are to be presented for in- spection at today’s Survival and Emergency Ration Conference. Despite the definite progress that has been made in the basic physiologic aspects of the survival problem, and the equally encouraging advances in the developmental phases, there yet remain many problems which require urgent answer. As a means of pointing up the host of details involved in “perfecting” a ration, some of the more immediate problems may be enumerated. One basic problem lies in the fact that practically all of the data obtained on human volunteers are predicated on the availability of 800 cc. of drinking water a day, while living in a temperate environment. There is, of course, no real assurance that such will be available to every castaway, and what is perhaps more pertinent, there is considerable likeli- hood that in the Arctic such an amount would not be available unless adequate fuel for heat, and perhaps, shelter, are provided. It is strange to conceive of lack of water in the midst of ice and snow, and yet the results of recent Arctic trials indicate that for the castaway in those regions the melting of ice would take much time, and heat, particularly if he were without shelter. It is a basic premise for survival feeding that the less the available quantity of drinking water, the closer one is forced towards a pure carbohydrate ration, if renal losses of body fluid are to be kept at a minimum. With further reference to the Arctic itself; there is great need for determining the effect of cold upon survival requirements. Certain technical questions remain which may require repeating or extending the inves- tigative work done earlier. Thus, it would be desirable to extend the experimental periods used in order to determine the effects found during experimental periods of a few weeks; it would also be desirable to compare the relative effects upon*urine volume of lactalbumen and egg protein when the former is ash-free; and possibly, additional investigation might be done on the effects of methionine when added to the diet in larger and smaller amounts. Some work is already underway in these connections. There are other problems related to determining which combinations of protein might produce an effect upon nitrogen sparing that exceeds that found to occur when egg protein alone is used. The well-known “supplementary” value of two or more proteins used together in a diet should be exploited fully so that not only is a maximum effect obtained in the physio- logic sense, but what is probably of more practical concern, so that food items may be de- veloped without restriction as to one main type of protein. Such a restriction begets arti- ficiality, and no artificial ration is likely to attain ultimate success. The possibility of devising a survival ration for use in all environments is an enticing but elusive goal. There is some question as to whether or not an “all purpose” survival ra- tion will ever be realized.* It is known, for instance, that calorie requirements are much greater in the Arctic than elsewhere, due mainly to the three factors mentioned previously. This requirement could be met by more quickly using up the supply of the survival ration, but this obviously may decrease the length of time the castaway will hold out, and if the water supply were not increased commensurately, the amount of protein consumed would be in ex- cess from the standpoint of conserving body water. Of even more immediate importance than 11 this, however, is the wide difference in packaging and stability requirements that character- ize extremes of environment. The difficulties in the tropics would seem to be chiefly those of stability, although packaging problems there are by no means non-existent. In the Arctic, both packaging and stability are involved, in ways that may not be immediately apparent un- less one visualizes the difficulties of removing packaging in the extreme cold and eating food which, although frozen when it comes into use, may have been stored previously in a heated warehouse and other supply points indoors or outdoors. The need for supplying the food in bite-sized pieces will also have to be determined, as well as the types and combinations of foods that are least thirst-provoking. We can, however, go only so far in the laboratory toward producing a finished item that will be acceptable as the Emergency and Survival Ration. Although it is obvious that many additional research and developmental problems remain to be solved, one of the most pro- mising directions for future progress would seem to lie in operational trials of the food items recently designed for this ration. The completion of such trials is now looked forward to as the source of critical information which will bring the Institute to the final stages of this project, and the attainment of a long sought goal. In the words of Larkin, The Quar- termaster General of the Army: “The development of a satisfactory Survival Ration is in- deed an important project, for the preservation of life is not only instinctive to man, it is also of,fundamental importance for successful military operation.” DR. BERRYMAN: We will now go on to the next topic on the program, which will be presented by Dr. King, who is known to all of you as an outstanding scientist and as the Scientific Director of the Nutrition Foundation. He will speak to you briefly of the contributions that have been made to the survival and emergency ration. Dr. King. DR. KING: Significant Contributions to the Survival and Emergency Problem It is unnecessary for me to review the research work that has been conducted in this field of emergency rations, because Dr. Berryman has already done that very thoroughly. Rather, I should like to comment on a few additional points related to the problems under discussion. First, when the World War II problems were uppermost in everyone’s mind, there was no adequate scientific evidence by which one could devise an emergency ration. It may seem strange, but that is true. I recall discussions in the National Research Council when we had the most able chemical, medical, and military officers that could be assembled to discuss the problem. They were dealing in theoretical terms, guessing, and no one there had an answer that was based on good experimental evidence. At one session, I recall they consider ed whether rum should be included in the emergency rations in Naval vessels. The fact that the British, who were certainly more experienced in naval affairs than we, had rum, led them to conclude that we were missing something. So they finally decided that the Navy should have rum in view of the British tradition; but within a week or two we received word the British had dropped it from their ration because its advantages were not supported by any good evidence 1 How tte rum was disposed of I am not informed. Again in a discussion of rations for aviators, one of the most competent medical authorities prepared a list of foods that aviators should eat and another list that aviators should not eat and, to my surprise and his, he had some of the same foods in both lists. You See, he was just reasoning without the benefit of experimental evidence. If you review step by step the work done on emergency rations, you will note that dur- ing almost every six-month interval, ngw pertinent information was brought to light. I watched it very closely and almost every progress report that came in had new information information that is now basic to any final or satisfactory solution to the problem. Again, I should like to emphasize the fact that there is still not sufficient experimental evidence by which to devise a satisfactory emergency ration. But on the basis of continuing research work there is brighter prospect of devising a good ration and it is becoming evident 12 that the problem is common to a great many areas of military operations. It is common to the Navy’s problem of men on emergency craft; it is common to the aviation problem, since no one knows where a man is to be dropped, whether on a raft, in the arctic or in tropical desert areas. But in getting data to guide plans for such situations, the evidence points strongly toward achieving the goal of a ration that is satisfactory in nutritional requirements, meets the emergency of a limited water supply, and provides for acceptability, space density and caloric density. The first approach to the protein problem was based chiefly upon need of protecting an individual subjected to hemorrhage, shock, or burns. The basic problem of general physio- logical welfare in maintaining the body protein reserve was of wide interest. The Harvard findings that weight for weight carbohydrate protected the body in regard to water supply more than water itself opened people’s eyes to the fact that they had a complex but practical physiological area here to study. The protein problem has gone through a similar cycle. There was a tendency to say. Well, provide carbohydrate, for if you don’t provide it, water and protein will be wasted anyway.” Now it is evident that there is a limit to the amount that one can spare the body’s reserve of water through reducing protein intake. Moreover, the caloric problem became very prominent in conjunction with the protein research. In conclusion, it seems to me that the record shows very clearly the practical value of continuing research work of the kind that has been under discussion at this conference. DR. BERRYMAN: The next paper will be presented by Dr. Pearl Swanson, of lowa State College. Dr. Swanson. DR. SWANSON: Utilization of Food Proteins Our interest in the utilization and metabolism of nitrogen had its origin in a study ini- tiated several years ago, that had to do with a determination of the nutritive value of the pro- teins of dehydrated eggs - a commodity at that time of strategical importance in the feeding of armies scattered all over the world. The experiment was planned to permit an evaluation of egg proteins in terms of Mitchell’s classic index, biological value. In this procedure, the rat is commonly used as the experimental animal. Measure- ments are made of the relative quantities of nitrogen ingested and excreted during a period of nitrogen-low feeding and in a subsequent period when a limited amount of test protein is incorporated into the diet. In comparing the excretions in the two experimental periods, workers have generally observed that the quantity of urinary nitrogen in the protein-feeding period exceeds the excretion when the low-nitrogen ration is administered. The difference between the two values represents the food nitrogen not “retained by the body for repair or construction of nitrogenous tissue”, and the biological value “is calculated as the per- centage of the absorbed nitrogen that is not eliminated in the urine.” However, imagine our surprise,yes, even our dismay, when the data collected in the course of rigidly controlled experiments did not permit the application of Mitchell’s defini- tion of biological value. In all cases the quantity of nitrogen excreted in the urine by rats when egg proteins were added to the nitrogen-low ration was less than that in the immediate- iy preceding period when only the protein-free diet was fed. On the other hand, when casein, gelatin, pork muscle or the proteins of rat muscle and rat liver were tested, the heretofore expected increments occurred. The data clearly indicated the nutritional superiority of egg proteins and suggested that these proteins were used more efficiently by the animal organism in the maintenance of es- sential processes than the animal’s own tissues. The development of a new index to express the nutritive value of the proteins was necessary. It was called “biological efficiency”, and aPparently was equivalent to Allison’s “nitrogen balance index” proposed independently at about the same time. 13 The recent great war has brought to a focus the realization that knowledge is inadequate for the intelligent feeding of men forced to live on restricted rations for any period of time. The formulation of a satisfactory “survival ration” has become an important project of the Quartermaster Corps of the Army faced with the responsibility of feeding men under emer- gency situations when full, well-balanced rations can not be provided. Such a ration must be able to withstand variations in environmental conditions without deterioration, prove accept- able to the consumer, and contribute toward the maintenance of normal physiological function ing of the body. The experiments just described indicated that eggs might be particularly useful in the formulation of emergency rations. However, the problem of their inclusion was beset with complications. The introduction of eggs into a ration raised problems regarding keeping qualities, possibilities of combination with other food materials, and final acceptability of the ration. In attempts to overcome these difficulties and to reduce the monotony of survival rations, the use of other food proteins was indicated. Before steps could be taken to so en- hance the palatability, texture, variety, and keeping qualities of the ration, the nutritional value of proteins that seemed suitable for the purpose needed to be established in terms of the new index. Furthermore, it appeared desirable from the standpoint of securing additional diversity, to evaluate combined as well as single food proteins. It seemed possible that by judicious combination, a variety of proteins might be introduced into the diet that collectively would have as important a biological effect as egg proteins. The first part of the report lam to make, therefore, was specifically planned to secure information regarding the biological efficiency of as large a group of single and combined food proteins as possible. PART I The Nutritional Value of Various Proteins and Protein Mixtures Pearl Swaps on and Hazel Metz Methods Used and Plan of Experiment Interpretations of the nutritional value of the proteins and protein-mixtures studied are based upon data obtained in two consecutive balance tests. Male albino rats of inbred Wistar strain, 6 months old, were the test animals. In the first period, collections of food, feces, and urine were made over an interval of 7 days after the rat had lived on a nitrogen-poor diet for 11 days. Then the dietary modification was introduced. Four days were allowed for adjustment to the diet, after which the nitrogen balance was determined again over a 7-day period. The basal nitrogen-low diet contained dextrin, 73 per cent; butterfat, 10 per cent, lard, 10 per cent; Osborne and Mendel salts, 4 per cent; NaCl, 1 per cent, and ruffex, 2 per cent. This ration was fortified with a mixture of pure vitamins including all known members of the B-complex, ascorbic acid and vitamin E, rice bran polish and cod liver oil. ' The diet was fed ad libitum in the first collection period when the low-nitrogen diet was* fed. In the second collection period when the test protein supplemented the ration, a quantity of food equaling the average daily intake in the first collection period was offered. The ani- mals consumed on the average, 49 Calories per day. In assessing the nutritional value of the specific proteins studied, their influence on the quantity of nitrogen excreted in the urine is one key that may be used. However, the data permit the calculation of other indices that give better pictures than the quantity of urinary nitrogen excreted under the conditions of this experiment. The first, “body nitrogen spared”, represents the algebraic difference between the balance characteristic of the nitrogen-low feeding period and that of the second metabolism period when the test protein is fed, i.e., it is a quantitative expression showing the extent to which the negativity of the nitrogen balance on a protein-free diet is reduced under the con- ditions of the experiment by the incorporation of protein in the ration. 14 Body nitrogen spared like the nitrogen balance in the egg-feeding period bears a linear relation to the quantity of nitrogen ingested.* It is possible, therefore, to relate this value to either food nitrogen absorbed or to food nitrogen ingested. The first ratio has been adopt- ed for the expression of nutritional value in the lowa State College laboratory, and has been designated as “biological efficiency.” An objection to the use of this index arises from the fact that the calculation of food nitrogen absorbed is based on the theoretical assumption that the excretion of fecal nitrogen of metabolic or physiological origin remains constant during the two experimental periods. That this does not always occur is illustrated by data presented herein. Note the experiments with rice. Whether such depression is of bacterial or metabolic origin has not been determined. In view of this observation, reference of body nitrogen spared to food nitrogen ingested might constitute a less complicated index than biological efficiency. This relationship has been determined in the present investigation and has been referred to as the “utilization ratio.” Three groups of experiments were conducted. In the first the nutritive values of the proteins of dried whole egg, polished rice, dried brewers yeast, and lyophilized skim milk were determined. The results of the first experiment indicated that the proteins present in milk were considerably less efficient than those of eggs and rice. The next experiment (n) was designed to check this observation, and to evaluate the validity of the proposed indices from another experimental angle. The nutritive value of a sample of the same lot of lyophilized skim milk used in Experiment I was retested. Simultaneously, lactalbumin and casein, the princi- pal protein constituents of milk, were studied not only singly but also combined in the pro- portions in which they are found in milk (casein: 90 parts; lactalbumin: 18 parts). This mixture is designated throughout the manuscript as “synthetic” milk protein. Experiment in was suggested by the fact that a number of the individual and natural mixtures of food proteins examined were found to be of superior nutritive quality. The Quartermaster Corps of the United States Army has suggested that the acceptability of an emergency or subsistence ration might be greatly enhanced by the substitution of a mixture of protein for a single protein in its formula. An attempt was made, therefore, to combine several sources of protein in such a way that the resulting mixture would be equivalent in nutritive value to some of the most efficient proteins known. In making these mixtures, proteins of high nutritional value that lent themselves well to combinations of pleasing tex- ture and flavor were selected. The following combinations were used; 1. a mixture of one-third egg proteins and two-thirds rice proteins; 2. a mixture of one-third egg proteins and two-thirds milk proteins; 3. a mixture of one-third egg proteins, one-third rice proteins, and one-third milk proteins; and 4. a mixture of one-half egg proteins, one-fourth rice proteins, and one-fourth milk . proteins. The milk protein represented in the above combinations was an artificial mixture being composed of pure casein** (80 per cent) and lactalbumin*** (18 per cent), i.e., synthetic milk protein. Results Inspection of Table 1 reveals, as in earlier experiments, that when dehydrated eggs served as the source of dietary protein in period 11, the excretion of urinary nitrogen was depressed below that observed when the low-nitrogen diet was fed. The average total output in the 7-day period was decreased by 67 mg. in the first test and by 81 mg. in the second test. On the other hand, yeast, rice, or milk proteins fed in the same quantity (3.5 per cent of the total ration) seemed to introduce no marked change in the quantity of nitrogen eliminated in the urire. The changes fell within the range of variation that may occur in rats fed the low- * Unpublished data. Files, Poods and Nutrition Section, lowa Agricultural Experiment Station, Project 799. ** Labco casein, vltamln-free; purchased from The Borden Co. **♦ Casein-free lactalbumln; purchased from Harris Laboratories. 15 Metabolic data Egg proteins Rice proteins Yeast proteins Milk proteins**** Test 1 Test Test 1 ' Test 2 Pd. I Pd. II Pd. I Pd. II Pd. I Pd. II Pd. I Pd. II Pd. I Pd. II Pd. I Pd. II Body wt. (gm.) 257 252 271 272 258 249 * 27’5 269 268 256 261 253 Dry food (gm.) 74 73 79 76 77 79 76 75 80 78 80 80 Calories eaten (no.) 348 350 368 365 363 350 353 327 372 360 377 370 Food N (mg.) 47 453 60 469 48 436 58 440 49 470 49 472 Fecal N (mg.) 175 184 145 185 185 147 143 138 178 248 170 214 Food Fecal N (mg.) - 9 - '40 - 0 - 0 - 70 - 44 Urinary N (mg.) 290 223 309 228 322 312 335 316 311 329 293 317 Total N loss (mg.) 465 407 454 . 413 507 459 478* 454 489 577 463 531 N balance (mg.) -418 + 46 -395 + 56 -459 - 23 -420 - 14 -440 -107 -414 - 59 N absorbed (mg.) - 444 - 429 - 436 - 440 - 400 - 428 Body N spared.{mg.) - 464 - 451 - 436 - 406 - 333 - 355 B.E .*(%) - 104 - 105 - 100 - 92 - 83 - 83 C.D.**(%) - 98 - 92 - 100 - 100 - 85 - 91 U.R.***(%) - 102* - 98 - 100 - 92 - 71 - 75 TABLE 1. AVERAGE METABOLIC DATA OBTAINED IN 7-DAY BALANCE TESTS: RATS FED NATURAL FOOD PROTEINS IN PERIOD II ♦Biological efficiency ••Coefficient of digestibility •••Utilization' ratio ••♦•Lyophlllzed milk 16 nitrogen diet (mean excretion of 290 rats, 291 mg.; standard deviation, 44 mg.)*. It should be noted that in the two experiments in which the nutritive value of rice proteins was studied, the trend was toward a depression of urinary nitrogen; while with the yeast and milk proteins there was a tendency toward an elevation in nitrogen excretion. As explained above, the percentage relationship of body nitrogen spared to food nitrogen absorbed is biological efficiency. Egg proteins in the first test thus received a value of 104 and in the second test, 105. The two values obtained for rice proteins were 100 in Test 1 and 92 in Test 2. The fact that the rice tested was purchased in two lots may explain the difference in results. Yeast and milk proteins both had average values of 83. The index, utilization ratio, presents the total picture of prot'in utilization. The average utilization ratios of the various food proteins were: eggs, 102 and 98; rice, 100 and 92; yeast, 71; milk, 75. In the second part of this unit of the investigation, the results obtained in Experiment I were evaluated. Table 2 presents the metabolic data and the nutritive indices determined in this experiment. By comparing the urinary nitrogen excretions resulting from the incorpora- tion of these proteins into the basal non-protein diet in quantities equivalent to 3.5 per cent of the ration, it is seen that lyophilized milk and synthetic milk proteins both gave rise to a slight increase in the excretion of urinary nitrogen, the quantity of body nitrogen spared by ’the various sources of milk proteins was greatest for lactalbumin, i.e., 457 mg., as compared with 324 mg. for lyophilized milk, 361 mg. for synthetic milk proteins; and 312 mg. for casein. The biological efficiencies for lyophilized milk and for synthetic milk protein were both 83. This was also the value obtained for lyophilized milk in Experiment I. Lactalbumin and casein similarly evaluated received ratings of 106 and 72, respectively. Thus, the value for the mixture of proteins found in milk is intermediate between the values obtained for its con- stituents, lactalbumin and casein, being related to the approximate proportions of each pro- tein present. The results obtained in Experiment 111 when various protein combinations were tested are shown in Table 3. When the figures representing the quantity of urinary nitrogen excreted in the two metabolism periods are inspected, it is seen that there is a decrease in its excre- tion after the ingestion of each of the mixtures. The relative quantities of body nitrogen spared by the various protein combinations were: egg and rice, 432 mg.; egg and milk, 365 mg.; egg, rice and milk (one-third each), 438 mg.; and egg, rice, and milk (one-half egg), 402 mg. These figures seem to indicate that the proteins of the egg and rice combination were well utilized. The relative nutritive worth of mixtures containing one-third egg and two-thirds rice proteins; one-third egg and two-thirds milk proteins; one-third egg, one-third rice, and one- third milk proteins; and one-half egg, one-third rice, and one-fourth milk proteins was evaluated in terms of the indices reported below: 1. The biological efficiencies obtained for these combinations were 98, 94, 104, and 101 respectively. 2. The respective utilization ratios were 98, 85, 99, and 97. 3. The coefficients of digestibility were 100, 91, 96, and 96 respectively. These data show that proteins lending themselves for use in survival rations may be so combined as to yield miktures that approach egg proteins in nutritive value. Unpublished data. Piles, Poods and Nutrition Section, lowa Agricultural Experiment Station, Project 799 • 17 METABOLIC DATA Lyophilized milk proteins Synthetic milk proteins* Lactal- bumin Casein Pd. I Pd. II Pd. I Pd II Pd. I pd.n Pd. I Pd. II Body wt. (gm.) 284 274 276 271 265 259 272 263 Dry food (gm.) 76 74 80 77 80 78 76 74 Calories eaten (no.) 358 336 372 350 377 360 353 341 Food N (mg.) 59 428 61 445 49 460 58 459 Fecal N (mg.) 150 186 167 179 164 192 154 178 Food fecal N (mg.) - 36 - 12 - 28 - 24 Urinary N (mg.) 309 318 331 342 300 226 311 376 Total N loss (mg.) 459 504 498 521 464 418 465 554 N balance (mg.) -400 76 -437 - 76 -415 + 42 -407 - 95 N absorbed (mg.) - 392 - 433 - 432 - ’435 Body N spared (mg.) - 324 - 361 - 457 - 312 B.E. (%) - 83 - 83 - 106 - 72 C.D. (%) - 92 - 97 - ’ 94 - 95 U.R. (%) —. ... ... — - 76 r 81 ' - 99 - 68 TABLE 2. AVERAGE METABOLIC DATA OBTAINED IN 7- DAY BALANCE TESTS: RATS FED MILK PROTEINS FROM VARIOUS SOURCES •A oomolnatlon of casein and lactalbumln In the proportions In which they are found In milk., 18 TABLE 3. AVERAGE METABOLIC DATA OBTAINED IN 7-DAY BALANCE TESTS: RATS FED VARIOUS MIXTURES OF FOOD PROTEINS Metabolic data 1/3 Egg 2/3 Rice 1/3 Egg 2/3 Milk* 1/3 Egg 1/3 Rice 1/3 Milk 1/2 Egg 1/4 Rice 1/4 Milk Pd. I Pd. II Pd. I Pd. II Pd. I Pd. II Pd. I Pd. II Body wt. (gm.) 272 265 281 275 278 274 268 262 Dry food (gm.) 74 75 75 73 71 70 69 68 Calories eaten (no.) 348 338 353 343 328 319 325 319 Food N (mg.) 58 442 58 430 56 442 55 415 Fecal N (mg.) 164 151 143 183 144 163 145 161 Food fecal N (mg.) - 0 - 40 - 19 - 16 Urinary N (mg.) 310 275 321 288 327 256 327 269 Total N loss (mg.) 474 426 464 471 471 419 472 430 N balance (mg.) -416 + 16 -406 - 41 -415. + 23 -417 - 15 N absorbed (mg.) - 442 - 390 - 423 - 399 Body N spared (mg.) - 432 - 365 - 438 - 402 B.E. (%) - 98 - 94 - 104 - 101 C.D. (%) - 100 - 91 - 96 - 96 U.R. (%) - 98 - 85 - 99 - 97 ‘"Synthetic" milk protein used In all combined protein mixtures. 19 PART II Dietary Fat and the Nitrogen Metabolism of Rats Fed Protein-Free Rations Pearl Swanson, Wanda Willman, Miriam Brush, and Helen Clark An important event in the history of the science of nutrition occurred at the time when emphasis in research shifted from investigations dealing with the utilization and the meta- bolism of the proteins, carbohydrates, and fats to studies of the “importance of the little things in nutrition.” All-of us know of the interest that accompanied the identification, one by one, of these essential dietary components, and how our ideas of the adequate diet grew and developed. In its formulation, many of the basic concepts of the old masters regarding the role of the major foodstuffs were accepted. Perhaps it is because the characteristics of an adequate diet are defined more clearly today than they ever have been before that research workers in nutrition are learning that the metabolic pathways of these common nutrients'may take unexpected turns and deviations. This has been the experience in our laboratory. Some of the enthusiasm of the famous workers in the old German laboratories has been recaptured and it has not been difficult to imagine how Carl V. Voit felt when he wrote, according to Lusk’s translation, “imagine our sensations as the picture of the remarkable processes of the metabolism unrolled before our eyes, and a mass of new facts became known to us I” The data I am about to present make only a small contribution, but they do indicate the complexity of the processes governing protein, fat, and carbohydrate metabolism and the remarkable ad- justments that the body, under stress, can make. Experiments of the kind just reported suggested that the way of handling the data obtain- ed in the classic balance test might become an important instrument for studying the course of nitrogen metabolism under various conditions. In thus using the balance test, we came to examine the nitrogen exchange when variations in the energy value of the ration, both quanti- tative and qualitative, were introduced. The experimental plan described in Part I was again used. Standardized animals were observed in a period when a nitrogen-poor ration only was fed, metabolic materials being collected for the estimation of nitrogen balance. Then the dietary adjustment was made, and nitrogen balance determined again after an appropriate adjustment period. Metabolism in the two periods was then compared. In the first experiment to be reported, two basal protein-free rations were used: one, rich; the other, poor in fat. One, which shall be designated hereafter as the high fat ration, contained 20 per cent of fat, made up of equal parts of butter fat and lard. The other, the low fat diet, contained no fat except that present in the two drops each of the Wesson and cod liver oils fed daily. Each diet was supplemented with a synthetic mixture of known vitamins fortified with ricebran polish extract. The respective energy values of the two diets were 4.8 and 3.8 calories per gram. The two series of rats receiving these diets voluntarily ad- justed their food consumptions so that the average caloric intake in each series was 49 calories per day. In the first experiment, the effect of restricted energy intake on the nitrogen metabolism of the two test series of rats fed the two protein-free rations was studied. The various groups making up the experiment are shown in Table 4. I shall speak of the group fed the protein-free diet high in fat as Series I, the group given the similar diet low in fat as Series 11. Each series was made up of 24 rats. The respective diets were fed ad libitum in the pre- liminary and collection periods of the first balance test. Then each series was divided into 4 groups. Food was offered in such quantities to these groups that the caloric consumption of each series was maintained at 4 different levels. The quantity of food to be supplied to each animal daily was determined by dividing the total quantity of food consumed in the first metabolic period by seven and offering either this full amount or. 3/4, 1/2, or 1/4 thereof as the daily quota. Thus, the intake of every rat in the second test period was controlled by its intake in the previous collection period. The table shows that this experimental manipulation gave for the 4 groups of each series average caloric intakes that bore the general relation to each other as 4:3:2:1. Because every rat served as its own control, and because the plane of nitrogenous 20 TABLE 4 Average caloric intake per day of rats fed basal low nitrogen diets Percent of normal intake of Calories supplied by daily food High fat diet Series I Low fat diet Series II Period I* Period II Period I* Period n Cal. Cal. Cal. Cal. 100 47 46 51 49 75 47 35 48 36 50 51 25 47 23 • 25 54 13 48 12 metabolism was comparable in all animals in Period I, it was possible to measure the effect of caloric restriction on nitrogen metabolism by comparisons, first, of changes in excretion of nitrogen from Period I to Period II; and second, by comparisons of the character of the nitrogen exchange in the second balance period of each dietary group. ♦Pood offered-ad libitum Average data depicting the quantities of nitrogen excreted in the urine by the 8 test groups in the two balance periods are presented in Table 5. In column I under each diet heading in the table appear the average quantities of urinary nitrogen excreted in period I when food ad libitum was allowed; in column 11, the amounts eliminated in period II when the limitations on caloric intakes were imposed. In the third column, headed Difference, are the data that show the effect that the dietary manipulation had on the urinary excretion. Differences in the total excretions of nitrogen in Period I from group to group and from series to series are not significant. When the high fat diet was fed, an increase in the quan- tity of urinary nitrogen excreted in Period II occurred with each successive reduction of calories, thereby giving a measure of the extent to which the animal was forced to draw upon its own tissues for its energy needs as the caloric value of the ration decreased. For example, reducing the caloric intake of the animal to 1/4 its normal ingestion, caused an in- crease in the quantity of nitrogen excreted over that of the previous period of 254 mg. Inspection of the data showing the response of the rats given the low fat diet indicates that its administration profoundly affected the pattern of metabolic processes, particularly at the two lower levels of caloric intake. For example, 818'mg. of nitrogen were excreted in Period nby the “25% calorie” rats. This figure converted to its equivalent of body tissue indicates that these rats lost 27 gm. of body weight in the second balance test. The actual weight loss as averaged from laboratory records was 28 gm. in this interval; T 9 gm. of this weight loss can be ascribed to the reduction in the food quota. On the other band, like restric lion of calories, when fat was in the diet, brought about a loss in body weight of only 9 gm. Thus, an intensification of catabolic processes induced by the caloric restriction of the low fat diet is apparent. Nitrogen balance gives a better picture of nitrogenous metabolism than does excretion alone. The feeding of the low fat diet at the two lowest levels of caloric intake resulted in negative nitrogen balances of 325 and 425 mg. for example, while similar reduction of cal- ories as provided by the high fat ration resulted in negative balances of only 150 and 275 mg. respectively. The picture is so striking that it may be pertinent at this point to recall that certain dietary here represented experimentally, had their counterparts in feeding practices created by the demands of the World War and its aftermath, lam thinking particularly of the nutritional problems of the starving masses in war-ridden countries, of the underfed groups in prison camps, and of men of the military existing for days on survival rations. It ma7 be interesting to note in passing that the Life Raft Ration furnished by the Army in the recent war bore a marked similarity, quantitatively and qualitatively, to the low-calorie diet containing no fat used in these experiments. 21 TABLE 5 Average excretion (in mg.) of urinary nitrogen in 2 successive 7-day metabolism periods when protein-free rations are fed at 4 levels of caloric intake % of normal intake of Calories supplied by daily food in Period n High fat diet Low fat diet Period I % Period n Differ- ence Period I Period n Differ- - ence 100 295 210 - 85 280 185 - 95 75 310 263 - 47 272 211 - 61 50 265 289 + 24 283 594 +311 25 290 544 +254 249 818 +569 These data raised the question, if fat is needed, how much is needed? Is there a critical level below which the rate of nitrogen metabolism is increased? The next experiment was designed to test this point. Rations were made in which either 20, 15, 10, 5, or zero per cent of fat were incorporated. The rations were fed as before at the four levels of caloric intake, 120 rats' being used. The removal of 5 per cent of fat from the diet produced no great change in nitrogen metabolism. But, thereafter, the picture altered. Ten per cent of dietary fat was protective when one-half the needed calories were supplied but not tohen their intake was again decreased. Five per cent of fat in the diet seemed to exert no protective action on the conservation of nitrogen when the calories supplied were only one-fourth normal. In surveying the results of these experiments, earlier studies were recalled in which a marked body-sparingaction of methionine had been observed when it supplemented the high fat ration. How would it function under the dietary conditions of the present experiment? The amino acid, therefore, in a quantity equivalent to 4 mg. of nitrogen per day was offered to rats at the beginning of the second metabolism period, thereby supplementing the test rations at the four calorie levels. The 20 percent fat and the zero per cent fat diets only, were used in this experiment. At the three highest levels of caloric intake, the administration of meth- ionine with the high fat diet caused a reduction in the quantity of nitrogen excreted in Period H, both in relation to Period I and in relation to Period H in the control rats receiving no amino acid (Table 6). The data show also that the same phenomenon occurred when the low-fat diet was fed except that it was more marked than when the high-fat diet was used when the calories were reduced one-half or more. For example, with a 50 per cent caloric restriction, the supple- mentation of the low-fat diet with methionine prevented ths loss of 302 mg. of nitrogen (594 mg. - 266 mg.). At the 25 per cent level of caloric intake the increased catabolism is re- presented by an increase of 254 mg. of urinary nitrogen. This jumps to 569 mg. when fat is removed from the ration. The significant point is that the supplementation of the diet with 4 mg. of methionine nitrogen decreases the catabolism so that it proceeds at about the same rate as when the ration contained 20 per cent of fat (compare total excretions in Period H of 544 mg. and 577 mg.). Forbes, Swift, and their coworkers at the Pennsylvania State College have presented some extremely interesting work recently dealing with the effect of food fat on the efficiency of utilization of food energy. It seems that we, too, from a different experimental angle may be demonstrating that the action of fats in decreasing the specific dynamic action of proteins, in this case tissue proteins, leads to a retention of protein. Certainly there is evidence that under the conditions of the present experiment, fat and carbohydrate are not interchangeable in the diet, according to their metabolizable energy values - the isodynamic law of Rubner. That fat may have dietary qualifications beyond those ascribed to it at present is indicated. Perhaps - too, methionine in inducing nitrogen retention may act through its depression of specific dynamic effects. 22 TABLE 6 Excretion of urinary nitrogen by rats fed a basal protein- free diet and the same diet supplemented with methionine before and after dietary restriction of calories % of energy require- ment ingested in Period II High‘fat diet (20%) I II LoW'fat diet (0%) i rt Basal Urine N - calories adequate Urine N following calorie restriction Differ- ence Basal Urine N Urine N following calorie restriction Differ- ence Basa 1 low nitrogen diet only 100 mg./7 da. mg./7 da. mg./7 da. mg./7 da. mg./7 da. mg./7 da. 100 295 210 - 85 280 185 - 95 75 310 263 - 47 272 211 - 61 50 265 289 + 24 283 594 +311 25 290 544 +254 249 818 +569 Basal low nitrogen diet supplemented with 4 mg. of me thionine 100 315 188 -127 295 177 -118 75 310 215 - 95 270 204 - 66 50 298' 256 - 42 257 266 + 9 25 329 523 +194 281 577 +296 DR. BERRYMAN: Developmental work at the Institute on the Air Force Emergency Ration has resulted in the preparation of a number of food bars. Arrangements have been made to present samples of these bars to you at this time. It is requested that you record your rating of these bars on forms to be provided when you examine the samples. A report on these ratings will be given later today. I would like to present to you Dr. Dove of the Food Acceptance Branch of the Institute who will explain how your judgments should be recorded. Dr. Dove. DR. DOVE: Mr. Chairman, ladies and gentlemen: In the next few minutes you will have an opportun- ity to test 14 of the food bars that have been developed in the commodity branches of the In- stitute and proposed as possible components of the Air Force Emergency Ration. The ac- ceptability test we wish to conduct today may be conduct today may be considered the fifth in a series of tests. Perhaps there will be 10 or 15 more tests on the acceptability of these bars while their stability is being investigated. Furthermore, we will not consider accept- ability testing completed until a test has been made on an actual seven-day consumption Period to determine the effect upon thirst. We are pleased to have today an opportunity to secure the candid taste judgments of these officers and professional men who are so much interested in the type of ration that is wanted. Samples of 14 bars, each separately wrapped in waxed paper and coded, wjll be pre- sented in this test. The bars will be given to you in three groups, first five, then another five, then four. Each tester will have three rating sheets --one for each group of bars. (See Figure 1). We would like you to taste all samples within each group, then insert their numbers in order of preference on the sheet to indicate which of the group you like best, which next, and so on. Then in the column under each code number we would like you to rate each sample on a scale of 1 to 10 points. A descriptive term appears on the sheet for each numerical rating. For instance, “7” is described as “slightly off”, to describe a sample 23 Place Samples in order of preference on rating scale, and describe d ifferences; 1st Choice: 2nd Choice; 3rd Choice; 4th Choice; 5th Choice; 6th Choice; j * Name: Date ; Fig. 1 Acceptable 10. Excellent 9. Very Good 8. Good 7. Slightly off 6. Off, but acceptable Not Acceptable 5. Slightly undesirable 4. Definitely undesirable 3. Unpleasant 2. Very unpleasant lr Repulsive '••••• CQMD FORM NO 12-12 k (revised) 0 >4-4 W CD Eh p CD 1 11 I O c cd buO U O 24 which does not quite meet an individual’s standards for any characteristic, such as color, flavor, texture, or appearance. Finally you are asked to make comments on both favorable or unfavorable characteristics of each bar, giving criticisms on flavor, taste, odor, texture, potential thirst-provoking properties, satiety value, etc. When completed the record blanks will be taken up for calculating the results. These will be compared with previous results and reported to you this afternoon. Louise Seiter, technologist in the Food Acceptance Branch, will take charge now in the presentation of the samples with the assistance of other members of the Branch. Distribution of Samples. Intermission DR. BERRYMAN: We will resume our meeting now. The next paper will be presented by Dr. J. B. Allison of Rutgers University. Dr. Allison. DR. ALLISON; The Utilization of Proteins One of the most common methods of evaluating dietary proteins is to determine the minimum amount of nitrogen necessary to maintain nitrogen equilibrium in an animal. This minimum amount of nitrogen, however, is not a constant for any one protein but varies ac- cording to the physiological state of the animal, if, for example, the protein stores are great, more nitrogen is reeded to maintain nitrogen is needed to maintain nitrogen equilibrium than when the stores are low. Thus, less nitrogen is necessary to maintain equilibrium in a pro- tein-depleted than in a normal animal. The minimum amount of nitrogen needed to maintain equilibrium varies even in normal animals and is not a constant characteristic of dietary proteins. For that reason, we have used the concept of nitrogen balance index to determins the nutritive value of proteins. This index is the rate of change of nitrogen balance with re- spect to the nitrogen intake at any given intake. It is a measure of the efficiency of dietary nitrogen in maintaining equilibrium; it is a function of the amount of nitrogen retained in the body of the animal. The nitrogen balance index in the region of negative balance is constant in the normal animal and characteristic of the protein fed. Nitrogen balance indexes, varying from .35 to 1.5 have been determined in dogs, each index being characteristic of a protein source. The higher the index the better the nitrogen economy in the animal. Tie change in economy with the change in patterns of amino acids is illustrated by the following indexes determined before and after supplementation of a pro- tein with an amino acid. Casein has a nitrogen balance index of 0.8; supplemented with meth- ionine this index is increased to 1.5. A fibrin hydrolysate has a nitrogen balance index of •62; supplemented with methionine the index is increased to 1.2. The index of wheat gluten is 0.4; supplemented with lysine the index is increased to 0.8. Thus, the index does reflect changing amino acid patterns. Indexes greater than unity demonstrate body-sparing action by dietary protein. But the magnitude of the nitrogen balance index is affected by the physio- logical state of the dog and the caloric intake as well as the pattern of amino acids. Casein fed to protein-depleted dogs, for example, has a nitrogen balance index of .93 which is higher than the 0.8 found in the normal dogs. Casein fed to a normal dog but with 25 percent of an adequate caloric intake has a nitrogen balance index of 0.3. The remainder of this disucssion Is oriented toward these factors which affect nitrogen balance indexes and the utilization ol proteins by the animal. A reduction in the caloric intake below optimum increases the excretion of body nitro- gen but does not alter the nitrogen balance index until the intake is less than 50 percent of normal. When the caloric intake is less than this there is a very rapid reduction in the value °f the index to zero. A reduction in urine volume accompanies the decrease in calories. A normal 10 kg. dog, for example, will excrete approximately 200 ml. of. urine per day. When the caloric intake is reduced to 25 percent of the normal the volume of urine drops to about 25 50 ml. per day. This fall in urine volume is a result, in part at least, of reduced fluid intake. Whan egg white nitrogen is added to the diet and calories restricted, urine volume increases. Since tte nitrogen balance index of the egg white is practically zero under these conditions, the increase in urine volume is the result of a need to excrete larger amounts of waste nitro- gen. Given sufficient calories, on the other hand, the egg white nitrogen is completely retain- ed and there is no effect on urine volume, provided the animal is not put too far in the region of positive nitrogen balance. To summarize the effect of caloric intakes on the index, when the non-protein calories are reduced systematically, two types of responses are encountered. In the first type, where the caloric reduction is relatively small, the nitrogen balance index remains essentially constant. The utilization of dietary proteins is not altered by this small reduction in caloric intake. There is, however, an increase in the excretion of body nitrogen. In the second type, where a more severe caloric restriction is imposed, that is, where the in- take is less than 50 percent of adequate, there is a marked decrease in the nitrogen balance index, demonstrating a poor utilization of nitrogen. Studies on the supplementation of casein with methionine in the dog have demonstrated that proper supplementation with methionine conserves both body nitrogen and body sulfur. This conservation is marked in the region of negative nitrogen and sulfur balances where the animal is in a somewhat depleted state. Conservation of nitrogen and sulfur becomes less marked and disappears in the region of positive nitrogen balance where the animal becomes saturated with methionine and the growth processes are not as general. Thus, methionire is a very valuable supplement to casein and to other proteins lacking optimum amounts of meth- ionine, particularly when the animal is in negative ..nitrogen balance or in a protein depleted state. Excess methionine produces a pattern of amino acids, however, that is toxic. When excess methionine is added to casein the excretion of nitrogen is increased rather than de- creased, body tissues being torn down, possibly due to internal supplementation of tte ab- normal pattern of amino acids. Even though the nitrogen excretion is increased and the body tissue nitrogen in general is being torn down, the liver protein concentration is being built lip in these animals to concentrations above normal. Under these conditions of excess methionine certain globulin fractions of blood are also increased above control values. Thus, patterns of amino acids can bring about the building up of one_type at the expense of other types of tissue proteins. A pattern of amino acids deficient in ore of the amino acids fed to a protein-deplet- ed dog may bring about good regeneration of plasma proteins but that regeneration is at the expense of other tissue proteins, the deficient pattern of amino acids being supplemented from tissue proteins which are depleted during this process. Studies on protein-depleted dogs demonstrate that different patterns of amino acids will do different jobs in regenerating tissues in these animals. Even excellent proteins like lac- talbumin and casein will do different jobs. Lactalbumin favors, for example, the formation of the albumin fraction, whereas casein brings about an abnormal increase in the beta glo- bulin fraction of plasma. Other proteins, with what is generally considered poor patterns of amino acids, give excellent results in regenerating certain plasma protein but are very poor, indeed, for the regeneration of other tissue proteins. Ore of the best patterns of amino acids which we have found for the job of regenerating all types of tissue proteins in the animal is found in the mixture of proteins of whole egg. Thus, the study of protein utilization has two major phases, one of these being the effect of the pattern of amino acids on the job that can be done in the animal and the other being the effect of the physiological state of the animal on the utilization of this pattern of amino acids. It is our purpose to continue our studies on these two phases including in our researches a third phase, the effect of other dietary constituents such as the vitamins, fat calories, etc., on the utilization of proteins. DR. BERRYMAN: There is one more paper to be presented before lunch. It will be presented by Dr. David Schwimmer of New York Medical College, Welfare Island, New York City. Dr. Schim- mer. 26 DR. SCHWIMMER: Recent Findings on Project, Protein Metabolism Studies on Reduced Caloric and Water Intakes Dr. Berryman, ladies and gentlemen, the excellent presentations this morning by Drs. Berryman, Gelman, Swanson, and Allison have provided a clear background picture of the problems with which we are all mutually concerned. It is quite apropos to mention tere that our own progress has been materially aided by the grand coordinating activities of Dr. Lep- kovsky, who established a very firm liaison between our group and those of Drs. Swanson and Allison, and the unstinting advisory aid of Dr. King, who, it must be remembered, helped to initiate our studies. Without being repetitious, I should like briefly to review some of the high points in the progress of our experiments at the New York Medical College. We have been working on sur vival rations since 1945. All our studies have been with human beings, for whom, in the final analysis, these survival rations are intended. Until the end of 1946 our subjects were con- scientious objectors; since then we have utilized volunteer Army enlisted men from Camp Lee in Virginia. The basic plan of each experimental run has included; 1. A standardization period of 7-10 days, during which the subjects are fed a full diet of standard Army 10-in-l rations and unlimited water. 2. A deprivation or testing period of 10 days, during which the men are fed only an experimental ration in restricted quantity, and 800 cc. water daily. (In our very first experiment only was the deprivation period five days long.) 3. An observed recovery period of 5 days, during which the subjects again re- ceive a full complement of food and water. We have generally employed two to three groups of 4-0 men each, testing as many as 16 men at a time. The paired-run technique has been utilized, with a control group run in parallel with other test groups. For example, one group on a protein-free diet always accompanied other groups receiving isocaloric diets with varying quantities of protein. To date we have tested and studied 48 different experimental rations. As indicated by Dr. Berryman, our first observations concerned themselves with the minimal caloric levels that might be required to produce nitrogen utilization and its accom- panying decreased urinary volume. Initially we tried 400 calories daily, the level supplied by the standard Air Corps Life Raft Ration. This resulted in no retention whatever of the nitro- gen fed. t Then we jumped to 900 calories. This figure was chosen on the basis of Dr. Swanson’s work indicating that 50% or more of minimal daily requirements should be fed; 900 calories supplies this minimum if we figure the average 65-70 kg. man as having a 1500-1800 calorie daily basal expenditure. Again, however, there was no significant retention. Similar results were noted with 1200 calories. It was not until we hit 1500 and 1800 calories that a distinct improvement occurred in nitrogen utilization, with decreased total urinary nitrogen and urinary volume. This high level of minimal caloric requirement to produce nitrogen retention would mean quadrupling the standard daily Lift Raft Ration, a consideration of great importance in the light of the strict limitations of weight and space allotments in aircraft. Therefore meth- ionine supplementation was tried. As Dr. Berryman has told you, in contrast with the results °f Drs. Swanson and Allison with rats and dogs, respectively, our human subjects not only did not show any improvement in nitrogen metabolism, but actually appeared tqbe somewhat worse off than without methionine. Our observations were made at the 900 and 1800 calorie levels, with diets containing 0.0, 3.0, and 6.0 gm. nitrogen, respectively. The laboratory re- sults accruing from supplementation with methionine can be summarized as follows: 27 1. An increase in total urinary nitrogen 2. An increase in urinary urea nitrogen 3. An increase in urinary volume 4. An increase in total urinary solutes 5. An increase in'urinary ammonia nitrogen 6. An increase in the negative nitrogen balance 7. A decrease, in serum potassium concentration 8. An increase in urinary potassium The unfavorable effect of methionine on nitrogen metabolism here seems best explained by a possible species difference. It has been suggested, especially on the basis of Dr. Alli- son’s ooservations, that we may have used too much methionine. However, if we recall that Leon Milled in his work on dogs used 0.1 gm. methionirK per kg. body weight, then our 2.5 and 5.0 gm. supplements for 65-70 kg. men do not seem to have been excessive. Neverthe- less, I believe that Dr. Allison’s experience justifies repetition of our studies at a later date using 1.0-1.5 gm. methionine. In accordance with the suggestion of Dr. Chaikoff, we next studied the effect of periodic- ity of feeding. Three groups of four men each were fed identical 900 calorie rations supplying 3.0 gm. nitrogen. One group ate the whole ration at 9 A.M.; another group ate it in four feed- ings, at 9 A.M., 1 P.M., 5 P.M., and 9 P.M.; the third group ate the ration in 12 hourly in- stallments from 9 A.M. to 9 P.M. No demonstrable difference was observed with the different regimens. The same experiment was repeated at the 1200-calorie level, and here the single- feeding group appeared to be somewhat better, but the results cannot be stated to have been statistically significant. Although the' greatest portion of our work has utilized dehydrated egg white as the source of protein nitrogen, some work has been done with other types of protein- The results, briefly, indicated that dehydrated egg white is markedly superior to protein derived from malted milk and to lactalbumin. With respect to lactalbumin, however, it must be said that the product we had contained almost 9% ash, and probably does not represent the optimal lactalbumin available. Further observations on lactalbumin and casein are indicated. Another aspect of the survival rations problem which is of great importance is the ques- tion of caloric output. This is especially of major concern in arctic areas, where the intense cold required the expenditure of large quantities of energy to maintain body temperature and heat inspired air. We had originally entertained the notion that Dr. Swanson’s previously mentioned “ 50%-of-caloric-re quire me nt” minimum might apply to total caloric expenditure, rather than to basal caloric expenditure; this idea was strengthened by our failure to obtain improved nitrogen utilization below 1500 and 1800 calories. Therefore we tested two groups of men at 1800 calories. One group was ambulatory in the Research Unit ward, according to our usual procedure. The other group marched 12 miles daily at four miles per hour, there- by expending an additional 600-700 calories. We were indeed surprised to find the nitrogen picture about the same in both groups. Thinking that perhaps the 600-700 calorie increment in energy output had been insuffi- cient to produce a sufficiently great difference, we followed the suggestions of Dr. Herbert Pollack, whom I see here in the audience today. He advised, on the basis of his own studies at Camp Lee during the war, that our exercising group march with full 35-pound pack at the rate of three miles in-50 minutes, then rest 10 minutes to avoid building up an oxygen debt. In this fashion, each man would expend an additional 100 calories per mile. Following this procedure,, our exercising group marched 15 miles daily for 10 days, expending a calculated additional 1500 calories each day over the amount used by the men in the control group. In this experiment, too, there was no detrimental effect upon nitrogen utilization; if anything, the exercising group did perhaps a shade better than the control group. Perhaps the explanation for this phenomenon resides in a phasic effect of exercise. Every clinician knows that the patient at absolute bed rest loses nitrogen rapidly. A moderate amount of exercise improves the nitrogen metabolism, possibly by better tapping of reserve body depot fat for calories (cf. exercise in diabetics). Extreme degrees of exercise, carried out over long periods of time, will probably have a detrimental effect, especially when depot fat is exhausted. It is very evident that further studies must be made on this problem. 28 At this point, it is appropriate for us to return to the studies I described earlier at the . various caloric levels from 400 to 1800 daily. In those experiments, the daily ration supplied 3.0 gm. nitrogen, derived from 20.0 gm. dehydrated egg white. Since even at tte beneficial 1500 and 1800 calorie levels, the daily total urinary nitrogen excretion averaged 5.0 - 6.0 gm., it was decided to increase the daily intake of nitrogen to 6,0 gm. in an attempt to attain posi- tive nitrogen balance. That this occurred at the 1800 calorie level was not too surprising, but we were certainly not prepared for the excellent nitrogen retention observed when only 900 calories daily were fed. Repeated studies corroborated this, and it appears that a simple in- crease in the amount of nitrogen fed enhances the efficiency of nitrogen retention, even at low calorie levels. About the same time, we undertook studies on the effect of varying quantities of fat. All the aforementioned caloric observations had been made on diets containing 10% hydrogenated fat by weight. It was felt that if the content of fat could be increased, the highly desirable ob- jective of increased caloric density might be attained. Accordingly we tested three groups of subjects in parallel, feeding them all 900 calories, but with the contert of fat in the diets at graded levels of 10%, 20%, and 30%, respectively. All three levels of fat--even the 30%-- were taken for 10 days with no signs of digestive disturbance. This was contrary to our ex- perience early in 1945, when two subjects fed a ration with 25% fat suffered from nausea, ab- dominal discomfort and cramps. The probable explanation for the difference in gastrointes- tinal tolerance seems apparent now: in the more recent studies the fat was well mixed in the ration, whereas in the earlier work the fat had “bled out”. The demonstration that the digestive tract could tolerate 30% fat by weight in a ration not designed with an eye to palatability was not, however, the only result of this experiment. It also developed that the 30% fat ration--in contrast with the 10% and 20%--distinctly de- creased urinary nitrogen excretion and urinary volume. When we recall that the three test rations were isocaloric, it becomes evident that the nitrogen-sparing effect of 30% fat was not due to increased calories, but rather to something intrinsic in tie higher fat intake perse, From a very realistic and practical'standpoint then, these data I have given you mean that we have accumulated here the basis for suggesting a new survival ration. This ration, supplying 900 calories, containing 6.0 gm. nitrogen and 30% fat by weight, weighing about 180 gm., has maintained positive nitrogen balance, decreased urinary nitrogen, solutes, and vol- ume, and kept the subjects in good clinical condition. It is necessary that such a ration undergo further laboratory trial and study. Also, it is extremely desirable, especially if it be projected as an overall all-purpose survival ration for all the Armed Forces instead of just the Air Corps, that this ration be tried over a de- privation period longer than the 10 days so far used. Certainly the stresses and strains ap- plying over a long term differ from the short term, when much of what occurs may depend upon a carryover from the normal control state. To this end, we have set up an experiment to test this ration for a 40-day period. If the results approach those obtained to date in 10 days, we shall consider that real progress has been made. Time does not permit discussion now of various other data we have obtained on electro- lyte balance, blood sugar levels, urinary 17-ketosteroid excretions, and other endocrine findings. These will appear in forthcoming reports. In closing, I should simply like to stress very strongly that the type of basic research reported here by the several investigators must be continued, since there are still many areas where our physiological knowledge is extremely deficient. I would add, further, the plea that close liaison be maintained among the investigating groups for optimal results. Thus there can be a beneficial interchange of ideas by men all working towards a common goal. dr. Berryman: This concludes the morning session of this conference. For the afternoon session we will re-convene in this room after lunclr. 29 Luncheon (AFTERNOON SESSION) Developmental Aspects of Survival and Emergency Rations DR. BERRYMAN: This morning our discussion pertained to the research aspects of the survival ration. This afternoon we would like to review some of the developmental phases that have been worked on in the Institute laboratories. The chairman for this afternoon will be the present Director of Food Laboratories at the Institute, Dr. Howard D. Lightbody, who was formerly with the Food and Drug Administration and later with the Western Regional Research Labora- tory of the Department of Agriculture. It is a pleasure to present Dr. Lightbody. DR. LIGHTBODY: The morning’s part of the program was devoted to a report on the more recent advances in the basic sciences underlying specifically the survival ration development. Now we turn our attention to the development side. First, you must have been very much impressed with the complexity of the problem insofar as the basic sciences are concerned. The development man has to be cognizant of these results because it is his duty to apply them to the specific problem at hand. He knows the terms “biological value” and “caloric density”, he knows something of the interrelationships of carbohydrates, fats, and proteins; perhaps he must know something of the biological value of proteins in order to select the proteins that go into a ration. I suspect that most of the development people are very grateful that at the moment at least a vitamin requirement has not been introduced into this particular ration. The development people of coj rse must go much farther than the mere nutritional studies or the physiological studies. They must in their formulation know the acceptability of the product that is produced, and at times what appear to be some very excellent ideas turn worthless after they reach acceptability testing. They must consider availability of raw ma- terials, and they must be assured in formulation of their products that they are not presenting something that is not feasible to process. And then they must consider the stability or keep- ing quality of the product. Recently the development work in the Institute has been under the direct supervision of Dr. Fevold, and he and his group have been instrumental in bringing the development to the state that is represented by the ration that was presented to you this morning for your exam- ination and expression of‘acceptance. Dr. Fevold will discuss for you the present state of emergency ration development in the Institute. Dr. Fevold. DR. FEVOLD: Discussion of Survival Ration and Emergency Food Items Recently Developed This morning we heard about the physiological aspects of survival nutrition and how our ideas have changed from those which prevailed during the last war, in which it was believed that the individual under survival conditions must eat only carbohydrates in order to preserve water. With the development of newer information we now know that if the individual under such conditions has 1800 calories per day he may eat carbohydrates, fat, and protein, pro- vided they are in proper balance, and still preserve water equally well or even better than is the case if he eats carbohydrates only. That finding suggested the possibility of develop- ing survival rations which would not only have the right composition with respect to carbo- hydrates, fat, and protein, but which would also have the right texture and acceptable flavor. In other words, the possibility was opened up for developing rations with higher acceptability than those used during the war, which consisted only of carbohydrates. The present problem is concerned with tie development of such items, and if that development is successful we will enlist for the benefit of the survivor not only additional physiological factors but also psychological factors, which were pointed out as being almost as important as those of a physiological nature. 30 Tte Quartermaster Food and Container Institute was charged with the task of putting this information to practical use in the development of such rations. A description of the de- sired rations or ration items was contained in the directive dealing with the initiation of the new project. Although much of this information has beep mentioned this morning, I would like to read a portion of this directive to indicate the objectives set up when this development was begun. We shall then see how much we have accomplished thus far and how much remains to be done. The following is the statement of requirements which has been submitted by tte Aero Medical Laboratory (15 January 1947): 1. Nutritional requirements of the ration (a ration is the supply of food for 1 man for 1 day.) a. Total daily caloric intake - 1800 calories per man per day b. Proportions of nutrients - Protein: 35-40 gms. per day (8-10% of calories) Fat: 40-60 gms. per day (20-30% of calories) Carbohydrates: 275-325 gms. per day (60-70% of calories) Vitamins and minerals: As provided in the natural food composition of the ration. c. Food composition - Protein sources of highest nutritional value (e.g., largely from dehydrated whole egg or egg white, rice flour, dehydrated skimmed milk); fat sources to be non-rancid and subject to a minimum of deterioration (egg yolk, shortening); and carbohydrates chiefly from dextrins, soluble starches (rice flour) and sucrose. d. Highest order of acceptability - The ration to be palatable, edible under extremes of temperature (-50° to +l2o° F.), non-thirst provoking (subjectively), swallowed easily with restricted free water supply (approximately 800 cc. per man per day), and varied in form, color, flavor and consistency. (Tte latter may be achieved in part by .providing the daily ration in tte form of three items, such as a sandwich- cookie, a nougat bar, and a cheese biscuit. Flavors should be mild and not too sweet.) 2. Military and technical requirements: a. Maximum caloric content with minimum weight and cubage (bulk or space.) (1) Caloric density: Equal to or greater than 4 calories per gm. (2) Total weight of ration: Equal to or less than 450 gms. per ration. (3) Total cubage of ration: Equal to or less than 30 cubic inches per ration. b. Stability and durability: (1) Eighteen months’ storage without impairing acceptability and nutritive value. Qt mubt withstand: 6 months at 100° F. Short periods at 120° F, (up to-2 weeks). Repeated freezing and thawing (-65° F.)TJ Those are the requirements to be met by tte ration we are attempting to develop. As you will notice, they are quite rigid, and for that reason a ration meeting all those require- ments will not be developed overnight. I should mention here that a ration was developed earlier which was ideal from tte standpoint of composition in that it contained carbohydrates, fat, and protein in tte proper proportions. It did leave much to be desired from the stand- point of acceptability. In our recent attack oA the problem at the Institute we presented tte problem to each of tte branches of tte Product Development Division and suggested that they develop as many bars with as much variety as possible, in order that we might have a large number of bars from which we could later choose tte ones most suitable. Tte result of those investigations was that 18 barb were developed; these were examined in the laboratory for acceptability and composition. In general, bars varied widely in composition from a strictly cereal type to the confection type^ The first group of bars (Table I) which we termed tte cereal bars, were developed by the Cereal and Baked Products Branch of the Institute. These are first baked as a cake and then slightly compressed into tte form of a bar. The flavor can be varied as indicated but tte general composition is the same except with respect to flavor. Tte next type was the fruit cereal bar, which consisted of different amounts of cereal and fruit; namely dates and apricots, to give flavor. Tte cereals used were wheat and rice. 31 Table I COMPOSITION OF CEREAL BARS % Wheat Flour 24738 Soya Grits . 6.97 Rice Flour 3.48 Shortening 26.13 Dried Whole Eggs 8.71 Dried Egg Albumen 8.71 Sugar 20.91 Salt 53 Flavors Oatmeal 1 Cocoanut 5 Vanilla 4 Chocolate Malted Milk 3 Cheese 2 Table n COMPOSITION OF FRUIT -CEREAL SURVIVAL RATION BARS Bar Number 6 7 8 9 10 Ingredients % % % % % - Dates 10 10 40 30 30 Apricots, Evap'd. 50 50 20 30 30 Wheat-Puffed 5 -- 5 5 15 Rice-Puffed 10 15 10 10 .. Egg White-Dried 10 10 10 10 10 F at - Hy dr oge nate d 15 15 15 15 15 Five different bars were developed from those combinations. (Table IL) Tables 111, IV, and V give the composition of other bars of various kinds which have been developed. The ingred- ients are quite varied and quite different from those presented in Tables I and 11. Obviously the textures and flavors of the bars are equally varied. All of the bars were made up in small quantity in the laboratory and subjected to pre- liminary acceptability tests utilizing 20 individuals in the Institute. The order of their ac- ceptability is presented in Table VI. It is indicated that all the bars were within the accept- able range. The next step in the work was an attempt to put the bars together to form the ration described in the original proposal. Dr. Berryman made calculations concerning possible rations comprising different bars. For instance, the first 12 bars furnish 46 gm. of protein, 79 gm. of fat, but only 171.9 gm. of carbohydrates. The ratio is protein 2, fat 3.4, and carbo hydrates 7.4. Since the recommended ratio is 2:3:14, the lack of carbohydrates is apparent. A number of such possible combinations were calculated in the same manner. In every case the result was the same--the protein and fat ratio was fairly good but the carbohydrate was only approximately half of what it should be. The best ration which we were able to make up from the items available is presented in Table VII. In order to increase the carbohydrate, use was made of a starch-jelly bar which was available and which consists mainly of carbohydrate. This ration as presented furnished 1949 calories and the protein-fat-carbohydrate ratio is 2:2.8:10.2. Tte carbo- 32 Table m COMPOSITION OF MODIFIED “SWEETMEAT" BAR Sugar . 33.7 Vinegar ' 4.4 Milk Fat '. 3.7 Cocoanut Oil 1.9 Hydrogenated Cottonseed Oil 1.9 Whey (Dried) 3.7 Cheese (Processed American) 3.7 Skim Milk Solids 5.5 Peanut Butter 18.4 Egg White (Dried) 9.2 Water 14.5 Table IV COMPOSITION OF MISCELLANEOUS SURVIVAL RATION BARS Bar Number 1* 2** 3*** Ingredients %_ Egg White 6.8 7.5 7.5 Peanut Butter 31.8 35.0 Strawberry Jam 31.8 Dextrin 18.1 10.0 10.0 Soda Crackers 11.3 47.5 47.5 Cheese 25.0 Whey (Dried) 10.0 * Peanut Butter-Strawberry Bar ** Peanut Butter-Cracker Bar •** Cheese-Cracker Bar Table V COMPOSITION OF CONFECTION-TYPE BARS Bar Number 1 2 3* Ingredients %_ %_ Egg Albumen 4.5 8.7 10 Her she y Tropic Bars 90.0 Cocoa Butter 4.5 Chocolate Liquor (Dried) 60.2 Powdered Sugar 30.1 Fat 30 Sugar 60 * Vanilla Flavor, Raisins (10 gm.) or Dates (15 gm.) 33 Table VI ORDER OF ACCEPTABILITY AND COMPOSITION OF SURVIVAL BARS TYPE OF BAR Cal. Prot. Fat Carb. Comp. Rank per oz. g/oz g/oz g/oz Peanut Butter & Strawb. Jam 130 4.2 4.7 17.6 5 Modified Sweetmeat 121 4.9 5.4 13.3 6 Oatmeal Cereal Bar 145 4.9 8.5 12.1 6 High Date, Low Apricot, Wheat & Rice 113 3.1 4.4 15.3 8 Chocolate Liquor Base Confection 117 3.7 5.6 13.0 12 Cocoanut Cereal 146 4.9 8.7 12.1 13 Vanilla Cereal 145 4.9 8.5 12.2 13 Medium Date, Medium Apricot, Wheat & Rice 113 3.2 4.4 15.1 13 Chocolate Malted Milk 148 4.2 8.9 12.7 18 Medium Date, Medium Apri- cot & Wheat 113 3.4 4.4 15.0 19 Tropical Chocolate 149 3.1 8.3 15.5 20 Date & Vanilla 148 2.1 7.5 18.0 20 Cheese Cereal 130 6.0 9.4 11.4 21 Low Date, High Apricot, Wheat & Rice 112 3.4 4.3 14.8 23 Cheese & Cracker 130 6.0 5.1 * 15.1 25 Peanut Butter & Cracker 138 5.5 6.3 14.8 26 Raisin & Vanilla 147 2.2 7.7 17.2 26 Low Date, High Apricot & Rice 112 3.4 4.4 14.8 29 hydrate is still low but less than without the starch-jelly bar. You have samples of this ration which have been assembled for your observation and examination. That is tte state of development at the present time, and as you can see, there is still much to do. In a preliminary way the bars seem to be fairly acceptable. However, the com- position is not what it should be; mainly, there is too little carbohydrate. There are other things which remain to be investigated; for instance, we do not know their keeping properties, So far we have not had the opportunity to carry out the necessary storage studies. For these reasons we should prefer to have you consider the data as merely preliminary. The develop- ment is far from final, and we hope that no one came to this meeting expecting to hear us say that we had developed a ration, and that the job is finished. Actually, we have made a begin- ning but further work is necessary to bring us to the desired goal. DR. LIGHTBODY: We can now have a report of the food acceptance test conducted on the 14 bars presented to the conference this morning. This report will be presented by Mr. J. E. P. Libby of the. Food Acceptance Branch. Mr. Libby. MR. LIBBY: From the judgments recorded this morning the following data were extracted for each bar: (1) The Group Average Rating on one to ten scale (2) The Group Average Rank (3) Thg Percent of Group rating the bar “Acceptable”. The 14 items were then ranked from one to 14, going from best to worst, on each of the above evaluations. This operation serves to make the 3 evaluations directly comparable; the 34 Table VII SURVIVAL RATION (TENTATIVE) Weight oz. gm. Cal. Prot. Fat CHO I- I* I* Oatmeal Cereal Bars (4) 4 113 578 19.6 34.0 48.4 Sweetmeat Bars (2) 2 57 243 9.8 10.8 26.6 Peanut Jam Bars (2) 2 57 259 8.4 9.4 35.2 Date Apricot Bars (2) 2 57 222 6.2 8.3 30.6 Chocolate Malt Bars (2) 2 57 234 7.4 11.2 26.0 Starch Jelly Bars (2) 2 57 203 .1 .2 50.7 Hard Candy Squares (4) 0.6 17 66 16.5 Coffee Packages (2) 0.4 10 36 1.0 8.0 Orange or Grape Beverage Packages 0.2 7 28 7.0 Sugar Cubes (4) .8 20 80 20.0 TOTAL 16.0 452 1949 52.5* 73.9 269.0 RATIO 2 2.8 10.2 58.8 percent of protein'from egg sources. three ranks so obtained for each bar were now summed. In these final scores, the lowest score is the best over-all evaluation--the highest sum is the worst. The data so obtained are shown in Table L Corresponding data for an earlier test at the Institute are shown in Table IL The seven best were Oatmeal, Coconut, and Chocolate bars from the Cereal group; High Date and Medium Date with Rice from the Fruit group, plus Modified Sweatmeat and Peanut Butter and Jam from the Dairy group. The poorest two were the Cracker bars. The best seven, worst two, and intermediate five form well-defined classes--with significant differences in acceptability. In results of the Institute test the same seven items formed a distinct top class; the same five the intermediate class, and the same two the poorest class. The order in which the items appeared within a class varied slightly from Institute to conference but such variation was not statistically significant. Conference judges exhibited maximal possible variations. One judge classed five items as “Excellent, not thirst provoking, would wear well over a period of days”; another classed the same items as “Repulsive, very thirst provoking.” Average of such variations (standard errors of means) in the conference group were two to four times corresponding figures from the Institute. Average evaluations and variations showed no significant differences between the military and the civilian personnel of the conference. The significantly smaller variation in Institute results permits dependable evaluation with smaller groups--on the order of a third of the conference group to achieve the same re- sult. This phenomenon is chiefly attributable to the superior test environment of the Institute and to the experience of Institute judges. That experience does not make the judges a typical of the population is seen in the duplication of average ratings given by trained and untrained judges; rather, experience reduces variation through stabilization of the judges’ subjective criteria. DR. LIGHTBODY: The next paper will be presented by Capt. James A. Roth of the Aero-Medical Labora- tory, Wright Field, Ohio. Capt. Roth. 35 Table I RESULTS OF CONFERENCE TASTE TESTS ON ACCEPTABILITY CF SURVIVAL RAH ON BARS 5 September 1947 Cereals Mean Acceptability Rating Rank Mean Preference Rank Rank Percent Acceptable Rank Composite Rank Oatmeal 7.4 4.0 2.6 4.0 86 3.0 11.0 Coconut 7.3 6.0 3.0 8.0 84 5.0 19.0 Vanilla 7.2 8.0 3.2 10.0 85 4.0 22.0 Chocolate malted milk 7.5 2,5 2.5 3.0 91 2.0 7.5 Cheese Fruit 6.7 10.0 3.6 12.5 77 10.0 32.5 High Date, Low Apricot, Wheat and Rice 7.3 6.0 2.7 5.5 81 7.0 18.5 Med. Date, Med. Apricot, Wheat and Rice 7.3 6.0 2.7 5.5 83 6.0 17.5 Med. Date, Med. Apricot, Wheat 6.5 12.0 3.6 12.5 70 12.0 36.5 Low Date, High Apricot, Wheat and Rice 6.6 11.0 3.1 9.0 76 11.0 31.0 Low Date, High Apricot, Rice Dairy 7.0 9.0 2.9 7.0 78 9.0 25.0 Modified “Sweetmeat’' 3.4 1.0 1.6 1.0 97 1.0 3.0 Cheese and Cracker 5.6 14.0 4.0 14.0 57 14.0 42.0 Peanut Butter and Crack- er 6.4 13.0 3.5 11.0 65 13.0 37.0 Peanut Butter and Straw- berry Jam CAPT. ROTH: 7.5 2.5 2.4 2.0. 79 8.0 12.5 The Results of Recent Studies on the Air-Borne Life Raft Ration In the past several months we have undertaken a study of survival in the cold environ- ment as can be simulated in the all-weather chamber of the Aero-Medical Laboratory at Wright Field. Our project is yet in its infancy--one might even say, it has barely been conr ceived. Reporting our data today is premature. You will find, as we have, that without con- trol studies finished, the nutritional data are difficult of interpretation. Today’s presentation concerns only the first in a series of experiments to be conducted and thus constitutes at best a progress report. In order that we place proper emphasis upon the role of a ration in the total picture, I should like to point out a few of the factors upon which the chances for survival of a castaway depend. Assuming that the aircrew member bails out and that his parachute opens success- fully, his chances of survival depend upon his ingenuity in meeting circumstances and upon the integration of such factors as: Protection against the environment, equipment to facilitate rescue, necessity for energy expenditure, injury or sickness, water, and lastly food (Chart I). The inter-relationship among these factors is so closely knit that it is impossible to consider one without the others. Food provides energy for maintenance of body heat, the per- formance of useful work, basal metabolic processes and may be stored in the form of glyco- gen, fat and labile protein depots. The role of food and water in the prevention of physical 36 Table n RESULTS OF INSTITUTE TESTS ON ACCEPTABILITY OF SURVIVAL RATION BARS August, 1947 Me an Me an Cereals Acce ptability Rating Rank Preference Rank Rank Percent Acceptable Composite Rank Rank Oat me al 7.7 4.0 2.8 5.0 90 4.0 13.0 Coconut 7.4 6.5 3.0 7.0 83 7.5 21.0 Vanilla 7.3 8.5 3.3 9.5 79 12.0 30.0 Chocolate malted milk 7.4 6.5 3.0 7.0 83 7.5 21.0 Cheese 7.3 8.5 3.0 7.0 79 12.0 27.5 Fruit High Date, Low Apricot, 7.7 4.0 2.5 3.0 93 2.5 9.5 Wheat and Rice Med. Date, Med. Apricot, 7.7 4.0 2.6 4.0 93 2.5 10.5 Whe at and' Rice Med. Date, Med. Apricot, 1 7.2 11.0 3.3 9.5 87 6.0 26.5 Wheat Low Date, High Apricot, 7.2 11.0 3.4 11.5 82 9.0 31.5 Wheat and Rice Low Date, High Apricot, 7.2 11.0 3.4 11.5 80 10.0 32.5 Rice Dairy Modified “Sweetmeat” 8.0 2.0 2.0 1.0 89 5.0 8.0 Cheese and Cracker 3.7 14.0 3.8 14.0 74 14.0 42.0 Peanut Butter and Crack- 7.0 13.0 3.7 13.0 79 12.0 38.0 er Peanut Butter and Straw- 8.4 1.0 2.3 2.0 100 1.0 4.0 berry Jam deterioration is well known. The physiological inter-relationship of protection against the environment, energy expenditure, water and food will be illustrated in the data to follow on nitrogen, water and energy balances. If a plane has crashed in the Arctic, the greatest concern is protection against the environment. A carload of food would not effectively help unless the castaway has adequate shelter, clothing, sleeping bag, etc. Without them he could freeze to death before he could eat a fraction of the food. And yet, if he did not have some food, he might lack the strength and energy necessary to extricate himself from the hostile environment or to exercise hard enough to maintain a normal body temperature. To appraise the role of a ration in the arctic survival problem, we set out to study 4 rations: 1. “Developmental” AAF Emergency Ration, No. 1; a test ration providing 1950 calories per-day. 2. Starvation; serving as a negative control. 3. E-Ration; a positive control ration providing 4000 calories per day. 4. Parachute Emergency Ration; a control on current issue, providing 960 calories per day. Environmental factors--shelter, clothing, sleeping bag, temperature, wind velocity, etc.--were to remain constant in the first phase of the study, using a number of nutritional and metabolic indices. However, urgency for provision of a ration in survival kits to be used 37 SURVIVAL RATION LOCAL SOURCES FOOD EXPENDABLE SOURCES 1. DESALTING KITS 2. CANNED WATER LOCAL SOURCES 1. LAKES 2. STREAMS 3. ICE AND SNOW NON-EXPENDABLE SOURCES 1. SOLAR STILLS 2. RAIN PAULIN WATER PHYSICAL DETERIORATION 1. DEHYDRATION 2. STARVATION 3. KETOSIS 4. ELECTROLYTE IMBALANCE 5. NITROGEN RE- TENTION TRAUMATIC INJURIES, 1. FRACTURES, BURNS 2. HEMORRHAGE, SHOCK 3. INFECTION 4. INSECTS, SHARKS DETERIORATION IN MORALE EXPOSURE 1. MOTION SICKNESS 2. FROST BITE 3. IMMERSION FOOT 4. SALT WATER DERMATITIS 5. SUNBURN 6. SNOW BLINDNESS INJURY OR SICKNESS SURVIVAL OF A CASTAWAY DEPENDS UPON THE INTEGRATION OF NECESSITY FOR ENERGY EXPENDITURE CHART I DEFENSE OR SELF- PROTECTION 1. SWIMMING 2. PADDLING 3. WALKING OUT MAKING CAMP 1. COOKING 2. SHELTER 3. SIGNALLING 4. CHOPPING WOOD MAINTENANCE OF BODY HEAT PROPULSION ACCESSORIES 1. PADDLES,SAIL 2. SPECIAL FOOT GEAR CRAMPONS EQUIPMENT TO FACILITATE RESCUE SIGNALLING DEVICES 1. FLARES 2. MIRRORS 3. ELECTRONIC 4. “GIBSON GIRL” PROTECTION AGAINST ENVIRONMENT^ MOSQUITO PROTECTION SHELTER 1. TENT 2. LIFE RAFT CANOPY AIR MATTRESI REPAIR KIT 3. LOCAL SOURCE LEAN-TO IGLOO CLOTHING 1. FLYING CLOTHES 2. ANTI-EXPOSURE 3. PARACHUTE 4. LIFE PRESERVER 5. SLEEPING BAG SOURCES OF HEAT 1. STOVES GASOLINE ALCOHOL 2. HEAT TABLETS 3. WOOD SUNBURN OINTMENT 38 in the arctic theatre within the next 2 months forced our hand to turn immediately to the AAF Emergency Ration before doing the desired control studies. We had hoped to study a minimum of 10 subjects on each ration, but because of the ac- celerated request for a tentative solution and the fact that we had available only one full-time technician--our study was limited to two subjects and the number of tests performed was greatly reduced. Experimental Procedures The plan of study was divided into 3 periods: A standardization or control phase, ex- perimental phase and a recovery phase (Chart II). The control phase was a period of two weeks during which time “learning’! was accomplished in the psychomotor performance and mental tests and a program of physical training was initiated. The latter consisted of daily work periods on the treadmill, rope skipping and striking the punching bag. The physical training was deemed necessary because of the limitation in type of activity to be permitted by eventual confinement in the cold chamber. During the second week of the control phase, the subjects subsisted on a standard regimen consisting of E-Ration, 3000 calories per day, and a constant adequate fluid intake of 2500 cc. per day. The subjects were about their usual duties and kept accurate time-activity data from which metabolic cost could be estimated. The base-lire studies conducted during this control phase included: Mosenthal concentration and dilution kidney function tests; galactose tolerance and bromsulphalein retention liver function tests; daily 24-hour collections of urine for determinations of total nitrogen, total solutes, (freezing point depression) and routine urinalysis (sp.gr., pH, microscopic, albumen, acetone and sugar); fasting blood specimens every other day for non-protein nitrogen, sugar, hematocrit, sedimentation rate, red blood count, white blood count and differential; basal metabolism, electrocardiogram, chest x-ray, complete physical examination, body weight measured within an accuracy of one gram and psychomotor performance as reflected in finger dexterity, simple reaction time, code substitution and additional mental tests. During the experimental phase, the subjects suddenly entered a cold chamber (floor space 13.5 x 19 feet) in which were simulated the circumstances of survival following a crash landing in the Arctic. The temperature in the chamber was -20° F. lb0 F. and the .wind ve- locity 3 to 5 m.p.h. The subjects subsisted on a “Developmental” AAF Emergency Ration providing 1948 calories per day and a daily free fluid intake of 800 cc. The ration was eaten in 8 approximately equal portions; 7 of them at 2-hour intervals spaced throughout the day and the last portion was eaten as a snack during the night while in the sleeping bag. This feeding pattern was used to take advantage of the information gained from the study of Mitchell et al. (1); that is, body temperature was found to be more easily maintained in the cold environment when the subjects ate small frequent meals in contrast to the conventional three. They enter- ed the chamber in the morning and made their exit in the morning of the tenth day, completing a period of continuous exposure to the prescribed environment for 9 days. While the men were in the chamber, the following observations were made upon them: Body temperature measured with a rectal thermometer before getting out of the sleeping bag in the morning and again 30 minutes after getting into the. bag to sleep in the evening (usually at 8:00 A.M. and 10:30 P.M.); skin temperatures as registered with resistance thermometers taped to 6 re- presentative areas of the body (palm, forearm, foot, calf, abdomen and back) were recorded 4 times daily (usually at 8:30 A.M., 11:00 A.M., 2:30 P.M. and 9:00 P.M.); daily 24-hour col- lections of urire and fasting blood every other day were analyzed for the same constituents as in the control phase; Douglas bag collections of expired air were obtained during the various types of activity and analyzed with the Haldane apparatus for oxygen and carbon dioxide con- tent; correlation of this information with an accurate record of time-activity data made pos- sible a computation of total energy expenditure; psychomotor performance was tested daily and the men examined for evidence of frostbite, dehydration, fatigue, and deterioration in morale. After their exit from the cold chamber, the men were weighed accurately to determine cumulative weight loss and the studies made during the control phase were again repeated. The subjects subsisted on the control regimen of E-Ration, 3000 calories per day, and a con- stant free fluid intake of 2500 cc. per day during the 4-day recovery period of observation. The “Developmental” AAF Emergency Ration used in this’study is illustrated in Figure 1. It consisted of 6 egg nog bars, 2 cheese-cracker bars, 2 chocolate malted milk bars, 2 39 regimen 2500 CC. FLUIDS 3000 CAL. E - RATION 800 CC. FLUIDS 1948 CAL. AAF EMERGENCY RATION 2500 CC. FLUIDS 3000 CAL. E -RATION KIDNEY FUNCTION BODY TEMPERATURE, 2X / DAY LIVER FUNCTION TESTS LIVER FUNCTION TESTS SKIN TEMPERATURE, 4X / DAY URINE (24 HR. COLLECTION) URINE (24 HR; COLLECTION) URINE (24 HR. COLLECTION) TOTAL NITROGEN TOTAL NITROGEN TOTAL NITROGEN TOTAL SOLUTES TOTAL-SOLUTES TOTAL SOLUTES ROUTINE URINALYSIS ROUTINE URINALYSIS ROUTINE URINALYSIS BLOOD (FASTING) BLOOD (FASTING) BLOOD (FASTING) NPN NPN NPN SUGAR SUGAR SUGAR HEMATOCRIT TESTS HEMATOCRIT HEMATOCRIT SEDIMENTATION RATE SEDIMENTATION RATE RBC, WBG, HGB RBC, WBC, HGB RBC, WBG, HGB SEDIMENTATION RATE DIFFERENTIAL DIFFERENTIAL DIFFERENTIAL BMR BMR DOUGLAS BAG- 02 CONSUMPTION EKG EKG DAILY PHYSICAL EXAMINATION FOLLOW-UP PHYSICAL EXAM. CHEST X-RAY PSYCHOMOTOR PERFORMANCE PSYGHOMOTOR PERFORMANCE PHYSICAL EXAMINATION PSYGHOMOTOR PERFORMANCE BODY WEIGHT TIME - ACTIVITY DATA TIME - ACTIVITY DATA BODY WEIGHT TIME - ACTIVITY DATA DAYS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 CONTROL PHASE EXPERIMENTAL PHASE RECOVERY PHASE EXPERIMENTAL DESIGN CHART H 40 Figure 1. AAF EMERGENCY RATION "DEVELOPMENTAL" 41 FIGURE 2. EXPERIMENTAL AAF ARCTIC CLOTHING ASSEMBLY 42 FIGURE 3- HAND AND FOOT GEAR. THE SLEEPING ASSEMBLY FOR THE FEET APPEARS IN THE MIDDLE. 43 FIGURE AIR MATTRESS, EXPERIMENTAL AAP ARCTIC SLEEPING BAG AND PONCHO-SURVIVAL TENT, 44 FIGURE 5. SUBJECTS WALKING ON TREADMILL. 45 LEGEND URINE VOLUME. TOTAL URINENITROGEN. TOTAL URINE SOLUTES CONTROL- EXPERIMENTAL PHASE. RECOVERY- Figure 6. Course of urine volume, total urine nitrogen and total urine solutes during the 3 phases. NITROGEN BALANCE (Nb- N, -Ny) N, =22.2 Nu = 12.5 NB - + 9.7 Nj = 24.0 N 0 = 17.4 Nb = + 6.6 Nx = 6.66 N 0 = 8.48 Nb = -1.82 DAYS Figure ?• Nitrogen Balance. The figures are averages for nitrogen Intake, urine nitrogen and nitrogen balance in grams during the last 3 days of the control and recovery phases and the last 6 days of the experimental phase. 46 packages of starch-jelly bars (Chuckles), 6 packages of candy-coated gum (Chiclets), 2 bouil- lon cubes, 2 packages of soluble coffee product, 4 cubes of sugar, 1 bottle of halazone tablets, 3 cigarettes and a cellophane bag for left-overs. This ration provided 1948 calories per man per day (Table I) of which 65.3 percent came from carbohydrate, 8.5 percent from protein and 26.2 percent from fat. The ration contents weighed 456' grams of which 76.5 percent were carbohydrate, 10.0 percent protein and 13.5 percent fat by weight. The sources of protein in this ration were mixed; 46 percent from whole egg, 23 percent cake flour, 18 percent cheese, 4 percent malted milk, 2 percent chocolate and 7 percent from extractives of meat and coffee. Tie rationale for the nutrient composition was based largely upon the studies of Drs. Swanson, Allison and Schwimmer which you heard summarized this morning. The ration was processed by the Quartermaster Food and Container Institute according to requirements prescribed by the Air Materiel Command (2). The experimental Air Forces clothing assembly worn by the subjects while in the cold chamber is shown in Figure 2. It consisted of a modified cotton “sweat suit” for underwear, O.D. blanket trousers and jacket, and an outer garment of trousers and Parka jacket with double wool pile insulation covered with nylon. The insulating quality of clothing has been de- fined in do.units (3). One do represents the insulation necessary to keep a resting, sitting, man comfortable under prescribed conditions of environment; i.e., when temperature is +7o° F., air movement 20 feet per minute, and relative humidity less than 50 percent. The com- plete clothing assembly worn by the men had a do value of 4.5 as determined on the copper man. The hand and foot gear is illustrated in Figure 3. During the daytime the men wore lightweight wool socks, a shearling inner boot, and on the outside of this an all-rubber mukluk. The outer two parts of this assembly were taken off at night and a second pair of socks (in- termediate weight wool) and a wool pile sleeping boot were put on while in the sleeping bag. The hands were protected by a rayon finger glove, covered in turn by a woolen knit mit and a leather mit with fur on the dorsum of the hand. The men slept in their clothing inside of an experimental AAF arctic sleeping bag on top of a Quartermaster air mattress (Figure 4). The sleeping bag has ado value of 7.0 but the insulation provided by the air mattress has not yet been determined. An experimental AAF re on red poncho-survival tent covered the sleeping bag to protect it from condensation “snow.’’ Activities in the cold chamber were limited to sleeping (average 5 hours,4l minutes), lying in tie sleeping bag (4 hours,s4 minutes), sitting (2 hours.,37 minutes), eating (1 hour, 56 minutes), walking (7 hours, 9 minutes) walking on the treadmill (50 minutes)(Figure 5) and playing catch with an over-sized stuffed ball (55 minutes). Occasionally the men struck at a punching bag,and a radio-phonograph was available for their entertainment. Results The results of these studies have been summarized in the graphs and tables which follow and represent the data collected on one of the subjects. The data from the other subject re- flected the same pattern with few minor differences. In Figure 6 the course of 24-hour urine volumes, total urine nitrogen and total urine solutes through the 3 successive phases are presented. The urine volumes averaged 541 ccr during tie last 6 days of “deprivation” in the cold chamber, the total urine nitrogen 8.48 gm. and the total urine solutes 763 milliosmols. Nitrogen balance* is portrayed in Figure 7. The average nitrogen balance during the last 6 days of the experimental phase was -1.82 gm. The delay in return to control values for the urine volume and total urine nitrogen and the more positive nitrogen balance in the recovery phase may reflect the re hydration and nitrogen re- pletion of convalescence. The critical nutritional data are summarized in Table n. I would like to point out that these results are not as favorable from the standpoint of nitrogen and water balances as those obtained by Dr. Schwimmer (4). In his group of subjects exposed to room temperatures, expending approximately 2500 calories, and subsisting on a ration that provided 1800 calories per day with 15 percent fat by weight and 12,5 percent pro- tein (6.6 gm. N), the sole source of which was egg white, the average results were as follows: Nitrogen balance Is used here to Indicate the difference In nitrogen Intake and urinary nitrogen output. 47 TABLE I AAF EMERGENCY RATION COMPONENT QUANTITY weight CHO PRO FAT CALORIES gms. EGG NOG BARS 6 168 103.0 22.58 32.18 793 CHEESE-CRACKER BARS 2 56 22.2 10.72 15.84 274 CHOCOLATE-MALT BARS 2 56 38.6 5.34 8.6 253 STARCH JELLY BARS (CHUCKLES) 2 112 104.0 0.0 0.0 416 BOUILLON CUBES 2 8 2.0 1.0 0.0 12 SUGAR CUBES 4 22 22.0 0.0 0.0 88 GUM (CHICLETS) 6 24 18.0 0.0 0.0 72 COFFEE PRODUCT, SOLUBLE 2 10 8.0 2.0 0.0 40 TOTAL 26 456 317.8 41.6 56.6 1948 % - WT. 76.5 10.0 13.5 % - CAL. 65.3 8.5 26.2 TABLE B SUMMARY OF DATA EXPERIMENTAL RECOVERY CONTROL PHASE PHASE PHASE DIET (QMS.) CHO 409 (62.0) 317.8 (76.5) 411 (64.0) PRO 150 (22.6) 41.6 (10,0) 132 (20.2) FAT 102 (15.4) 56.6 (13.5) 102 (15.8) AVE. CALORIC INTAKE 3157 1948 3106 AVE. CALORIC OUTPUT 2990 3180 2610 BODY WEIGHT, POUNDS 150.8 143.9 149.4 N-INTAKE, GMS. 24.0 6.66 22.2 AVE. TOTAL URINE - N, GMS. 17.4 8.48 12.5 AVE. N-BALANCE, GMS. +6.6 -1.82 +9.7 AVE. TOTAL URINE SOLUTES, MOsm 1614 763 1435 AVE. URINE VOLUME, CC. 1765 541 1158 AVE. % LYMPHOCYTES 41 54 36 BMR -7 -9 Ave. Total Urine Nitrogen = 6.15 gm. Ave. Nitrogen Balance ■ = + 0.42 gm. Ave. Total Urine Solutes = 356 MOsms. Ave. Urine Volume * 347 cc. Under the conditions of his experiments, his ration was less dehydrating and imposed less solute and nitrogen load upon the kidneys. The more favorable results obtained by Dr. Schwimmer may be explained in part by the differences in sources of protein used in the rations as indicated in the studies reported this morning by Drs. Swanson and Allison. How- ever, there were other differences in experimental design which warrant consideration; namely, feeding pattern, environmental temperatures, activity and other minor differences in dietary composition. Total energy expenditure Was computed from oxygen consumption and time-activity data and found to average 3180 calories per day during the cold chamber run. This can be checked by a consideration of the various factors in energy expenditure (Table HI). Total energy expended is equal to that lost through the performance of useful work plus heat loss, heat lost through the clothing and sleeping bag, heat lost by warming inspired 48 TABLE HI ENERGY EXCHANGE TOTAL ENERGY EXPENDED, = W + Hcl + A + E1+Es = 3566 CALORIES W = USEFUL WORK = 10% OF TOTAL ENERGY (3180) = 318 Hcl = HEAT LOSS THROUGH CLOTHING AND SLEEPING BAG = 2200 A + El - HEAT LOSS THROUGH WARMING INSPIRED AIR AND EVAPORATING MOISTURE FROM LUNGS = 704 Es = HEAT LOSS FROM EVAPORATING INSENSIBLE PERSPIRATION FROM THE SKIN = TOTAL ENERGY EXPENDITURE ESTIMATED FROM OXYGEN CONSUMPTION AND TIME - ACTIVITY DATA = 344 35M~ 3180 MEAN TOTAL ENERGY EXPENDITURE = 3373 EFFECTIVE CALORIC INTAKE ( 1950 - 10%) = 1750 DAILY CALORIC DEFICIT = 1623 EQUIVALENT CUMULATIVE WEIGHT LOSS (9 DAYS) = 5.3 POUNDS TABLE IV - WATER BALANCE (9-DAY PERIOD) GAIN LOSS FREE FLUID .INTAKE 7200 URINE 4655 Wox EXOGENOUS 2340 INSENSIBLE WATER 7200 Wox ENDOGENOUS 1880 FECES 450 DIET WATER 405 11,825 12,30 5 cc. NET WATER BALANCE = -480 cc. 49 air and evaporating moisture from the lungs and skin, and heat debt due to cooling body tissues. Body temperatures never fell below 98° F. and skin temperatures remained within the range for comfort. It is, therefore, assumed for the purpose of these calculations that the heat debt was negligible. If one were to assume a work efficiency of 10 percent, the number of calories lost in this way would be 318 on the basis of a total caloric expenditure of 3180 calories. Ac- tually, the work efficiency for the 24-hour period might be more nearly 3 percent, equivalent to 95 calories. Heat loss through clothing is estimated from the equation: flcl = 2-09 (Ts - To) _ caiorles ic 1 “+■ I £ Ts = weighted skin temperatures = + 87° F. To = operative environmental temperature = -20° F. ICI = clo value of clothing =4.5 Ia = insulating value of air under conditions of the chamber = 0.3 From the number of hours spent in the sleeping bag and that out of the bag, and from the do values of the clothing assembly and sleeping bag, heat loss through this avenue was estimated to average 2200 calories per day. Heat loss via the lungs (warming air and vaporizing water) was estimated from the line chart in the NRC Report (CAM No. 390, Clothing Test Methods) to be 704 calories for air inspired at -20° F. On the basis that approximately 50 percent of the insensible water loss occurs through the skin and that 24 percent of the total heat loss occurs through evaporation of insensible water from both skin and lungs, it was estimated that 344 calories were dissipated in this manner. The total energy expenditure estimated by consider- ation of these various routes of heat loss was 3566 calories which checks reasonably well with the 3180 calories computed from oxygen consumption data. If we assume 10 percent loss through lack of digestion and absorption, the effective caloric intake would be 1750 calories and the daily caloric deficit 1623 calories. This would be equivalent to a cumulative weight loss of 5.3 pounds over the 9 days exposed to the cold environment (calculated from the total urinary N, oxygen consumption, CO2 production, pulmonary ventilation, total RQ and non-pro- tein RQ). Water balance for the 9-day period is-summarized in Table IV. and indicates a net loss of 480 cc. equivalent to a weight loss of approximately one pound. The combined calculated weight loss due to water and endogenous catabolism is 6.3 pounds compared to the observed weight loss of 6.9 pounds. The blood non-protein nitrogen, sedimentation rate, hematocrit, .white blood count and red blood count were consistently within normal range throughout the study and showed nb direc- tional trend or change. A relative lymphocytosis was observed in the subject with 71 percent lymphocytes present on the second day in the cold chamber, 63 percent on the fourth day, and averaging 54 percent over the 9-day experimental phase. Failure to demonstrate hemocon- centration or leukocytosis, which have been reported to occur as a result of cold stress, is understandable since our subjects were adequately clothed. Conclusion In conclusion it may be said that the maintenance of normal body and comfortable skin temperatures without the necessity for exhausting exercise and an average loss of only 6.1 pounds in body weight over the 10. T., and Brush, M. Biological efficiency of egg proteins, Proc. Fed. Am. Soc. ExpLßiol., 4:164 1945 75 Webster, A. P,, Commander, HS, USNR Ciioric Requirements of Man in Cold Climates (Theoretical Considerations), Rept. pub- lished by Research Div., Bureau of Med. & Surgery, Navy Department, 11 February 1947 Winkler, A. W., Danowski, T. S., Elkinton, J. R., and Peters, J. P. Electrolyte and fluid studies during water deprivation and starvation in human subjects and the effect of ingestion of fish, of carbohydrate and of salt solutions, J. Clin, Invest., 23:807 1944 Winslow, C. E. A., Herrington, L. P., and Gagge, A. P. Physiological reactions of the human body to various atmospheric humidities, Amer. J. Physiol., 120:288 1937 Wolf, P. A., and Corley, R. C. Significance of amino acids for the maintenance of nitrogen balance in the adult white rat Am. J. Physiol., 127:589 1939 Report of Proceedings, Conference on Survival Rations, QMC Subsistence Research Labora- tory, 20 August 1945. Report on Proceedings, Committee on Food Research Conference, Reduced Caloric and/or Water Intake as Related to Subsistence, held at Berkeley, Calif., 27 June 1946- Interim Report, Survival Rations: A Critical Review, Rations Dev. Branch, QMC Subsistence Research &, Development Lab., August, 1945. Report on Survival Rations at Sea to Committee on Med. Res., Office of Scientific Research & Development by E. M. Scott, July, 1945. 76 APPENDIX B 77 ATTENDANCE Allison, James 8,, Dir. Bureau of Biological Research Rutgers University New Brunswick, N, J. Quartermaster Food and Container Institute Chicago, 111. Buettner, Louis G., 2nd Lt., QMC Quartermaster Food and Container Institute Chicago, Jll. Anderson, J. A. Bureau of Biological Research Rutgers University New Brunswick, N. J. Gannon, Paul R., Chairman Dept, of Pathology University of Chicago Chicago 37, 111. Armstrong, J, G., Major Canadian Army Liaison Officer Quartermaster Food and Container Institute Chicago, HI. Conley, W. J., Jr. Commandant, USGG U. S. Coast Guard Washington, D. C. Barta, James C., Col. Strategic Air Command Andrews Field Washington, D. G. Conquest, Victor Dir. of Research and Development Armour & Co. Union Stock Yards Chicago 9, 111. Becker, C. W. Vice President in Charge of Research Wilson & Co. Chicago, 111. Gowgill, W. P., Ist Lt., QMC Quartermaster Food and Container Institute Chicago, ILL Behnke, Albert R., Capt. Director of Research Naval Medical Research Institute Bethesda 14, Md. Crowley, John E., Lt. Col. The Air Quartermaster Army Air Forces Washington, D. C. Belding, Harwood S. Director of Research Climatic Research Laboratory Lawrence, Mass. Dack, G. M., Dir., Food Research Institute University of Chicago Chicago 37, 111. Boyd, Richard K., Lt. Col, AGF Board No. 3 Fort Benning, Ga. Daggs, Ray G. Director of Research Medical Dept. Field Research Laboratory Fort Knox, Ky. Brenner, Sadie Chief, Nutrilite Section Quartermaster Food and Container Institute Chicago, 111. Deuel, Harry J., Jr., Head Dept, of Biochemistry and Nutrition University of Southern California Los Angeles 7, Calif. Brobeck, Johnß., Asst. Prof. School of Medicine Yale University New Haven 11, Conn. Dittman, H. Col., Hqrs*. Army Air Forces AC/AS-3, Reqn. Div. Washington, D. G. Broestl, Edward A., 2nd Lt., QMC Quartermaster Food and Container Institute Chicago, 111. Eng, Erling, 2nd Lt., QMC Quartermaster Food and Container Institute Chicago, Hi. Buck, Robert E. Fruit and Vegetable Products Br. 7 8 Freed, Myer Biochemist, Nutrition Br. Quartermaster Food and Container Institute Chicago, HI. Herron, J. G., Lt. USN Subsistence Division Bureau of Supplies & Accounts Washington, D. C. Fritzsche, Herbert, 2nd Lt; Quartermaster Food and Container Institute Chicago, 111. Hobson, Merk, 2nd Lt. Quartermaster Food and Container Institute Chicago, Illinois Goetzl, Franz Dept, of Medical Research Per mane nte Foundation Oakland 11, Calif. Holmes, F. W., Major, USMG Supply Department Hqrsn, U. S. Marine Corps Washington, D. G. Hunter, A. Stuart Technical Director Research and Development Branch, OQMG Washington, D. C. Goodenough, John 8., Capt. Quartermaster Food and Container Institute Chicago, 111. Jones, Wayne H., Capt. Quartermaster Food and Container Institute Chicago, Illinois Gorham, John D., Major Strategic Air Command Andrews Field Washington, D. G. Gustafson, G. E., Ist Lt., MC Clinical Investigation Division Medical Nutrition Laboratory Chicago, 111. Katz, Sam 2nd Lt. Quartermaster Food and Container Institute Chicago, Illinois Hammer, Frank J., Ist Lt. Quartermaster Food and Container Institute Chicago, 111. Keenan, Gregory F., Col. AAF Liaison Office Research and Development Branch, OQMG Washington, D. C. Harp, Charles H. Microbiological Branch Quartermaster Food and Container Institute Chicago, 111. Keeton, Robert W. Department of Medicine College of Medicine University of Illinois Chicago, Illinois Hartwig, Richard T., Ist, Lt. Quartermaster Food and Container Institute Chicago, 111. King, G. G., Scientific Dir. Nutr. Res. Foundation, Inc. Chrysler Building New York 17, N. Y. Hayes, Frank L. Chicago Daily News 400 W. Madison Street Chicago, Illinois Kmieciak, T. C. Chemist Food Analysis Division Quartermaster Food and Container Institute Chicago, Illinois Hemphill, Frances Technologist Fruit & Vegetables Products Br,, Quartermaster Food and Container Institute Chicago, Illinois Kocher, R. 8., 2nd Lt. Quartermaster Food and Container Institute Chicago, Illinois Henschel, Austin Dept, of Physiological Hygiene University of Minnesota Minneapolis, Minn. Last, Jules H., Capt. MG Medical Nutrition Laboratory Chicago, Illinois 79 Lewis, Richard L., Lt. Col. Research and Development Branch, M.P.D. OQMG Washington, D. C. Robinson, True W. Research Physiologist Aero Medical Laboratory Air Materiel Command Wright Field Dayton, Ohio Logan, Paul P., Col.Rtd. Dir. of Food & Equipment Research National Restaurant Association Chicago 3, Illinois Roth, James, Capt. MC Aero-Medical Laboratory Wright Field Dayton, Ohio Luker, James A., 2nd Lt. Quartermaster Food and Container Institute Chicago, Illinois Samuels, Leo T. Dept, of Biological Chemistry University of Utah Salt Lake City 1, Utah Melnick, Daniel Chief, Food Development Division Quartermaster Food and Container Institute Chicago, Illinois Schwimmer, David Metropolitan Hospital Research Unit N. Y. Medical College Welfare Island, New York 17, N. Y. Mitchell, H. H. Prof, of Animal Nutrition Agricultural Experiment Station University of Illinois Urbana, Illinois Shelesnyak, M. C. Head Environmental Physiology Section Medical Sciences Branch Office of Naval Research Navy Department Washington, D. C. Morse, W. C., Capt. Quartermaster Food and Container Institute Chicago, Illinois Soloski, Theodore Cereal & Baked Products Branch Quartermaster Food and Container Institute Chicago, Illinois Newton, Roy C. Vice Pres, in Charge of Research Swift and Co. Union Stock Yards Chicago 9, Illinois Spinella, Jane R. Chief, Medical Dietetics Division Medical Nutrition Laboratory Chicago, Illinois Peter, Hollis Food and Agric. Br. State Department Washington, D. G. Sporn, Eugene M. Department of Biochemistry College of Agriculture University of Wisconsin Madison, Wisconsin Pollack, Herbert Metabolic Clinic Mt, Sinai Hospital New York 29, N. Y. Stateler, E. S. Food Industries 520 N. Michigan Avenue Chicago, Illinois Rauch, A. G. Technologist Fruit & Vegetable Products Br. Quartermaster Food.and Container Institute Chicago, Illinois Stegeman, R. A. Dairy Products Branch Quartermaster Food and Container Institute Chicago, Illinois Reynolds, Orr E. Medical Sciences Division Office of Naval Research Navy Department Washington, D. C. Swanson, Pearl P. Prof, of Nutrition lowa State College Ames, lowa 80 Thurston, Emory W. Director The Emory W. Thurston Labs. Los Angeles, California Willingham, R. J. Bureau of Aeronautics U. S. Navy Washington, D. C. Voris, Leßoy, Exec. Secy. Food & Nutrition Board National Research Council 2101 Constitution Avenue Washington, D. C. Wilson, A. S., 2nd Lt. Quartermaster Food and Container Institute Chicago, Illinois Walliker, Catherine T. Food Acceptance Branch Quartermaster Food and Container Institute Chicago, Illinois Wiltamuth, Ralph H., Lt. Col. Hqrs., Army Ground Forces Ft. Monroe, Virginia Winokur, William G. Food Technologist General Products Branch Quartermaster Food and Container Institute Chicago, Illinois Walton, Robert C., Lt. Col. USMG Executive Office of the Secretary Navy Department Washington, D. C. Williams, H. J., Vice Pres. Wilson & Co. Union Stock Yards Chicago 9, Illinois 81 AGPC 81-19