NITROGEN BALANCE.—Oakman.

Average Intake.

NITROGEN BALANCE.—Henderson.

NITROGEN BALANCE.—Morris.

NITROGEN BALANCE.—Coffman.

NITROGEN BALANCE.—Steltz.

NITROGEN BALANCE.—Loewenthal.

NITROGEN BALANCE.—Cohn.

NITROGEN BALANCE.—Zooman.

NITROGEN BALANCE.—Sliney.

NITROGEN BALANCE.—Broyles.

NITROGEN BALANCE.—Fritz.

Third Nitrogen Balance.

The last of March, a third nitrogen balance was tried on a slightly lowered nitrogen intake and with a slight increase in the fuel value of the daily food. In this period of five days, March 28 to April 1, the nitrogen taken in per day averaged 8.62 grams, or nearly one gram per day less than in the preceding period. The fuel value of the food averaged 2840 calories per day, or about 300 calories more than in the preceding period.

The daily diet, with its content of nitrogen, etc., is detailed for each day under Oakman. Any deviation from this diet in the cases of the other men is indicated on the accompanying balance-sheets.

The results obtained in this balance period indicate that the lowest level had been practically reached, at least under the conditions of body-weight, food, and work prevailing. Cohn, Fritz, and Broyles showed a distinct positive balance. Steltz and Loewenthal were practically in equilibrium, the deviation being within the limits of error. The remaining six men showed a minus balance, although in no case was it very marked.

It is interesting to note in this connection that the average daily output of nitrogen through the urine for this five days’ period (Oakman’s case) amounted to 7.04 grams, being 0.2 gram less per day than in the preceding period. This figure for nitrogen in the urine means the metabolism daily of 44 grams of proteid.

Undoubtedly, the rate of proteid metabolism for these men could have been lowered considerably beyond the present level by increasing largely the intake of carbohydrates and fats, but it has been the intent throughout all of these experiments to learn the minimal proteid requirement under conditions precluding the use of any excess of non-nitrogenous foods; also, to study the effect of a general physiological economy in nutrition, with a view to ascertaining the real necessities of the body for both proteid and non-proteid foods with maintenance of bodily strength and vigor. Hence, we may again emphasize the fact that the low proteid metabolism maintained by all these men throughout the period of the experiment, with establishment of nitrogenous equilibrium on a consumption of proteid or albuminous food averaging one-half the amount ordinarily specified as the daily requirement of the healthy man, has been accomplished with even less total food—fats and carbohydrates—than the ordinary standards call for, i. e., considerably less than 3000 calories per day in fuel value.

OAKMAN.

Monday, March 28, 1904.

Breakfast.—Fried rice 150 grams, syrup 75 grams, baked potato 250 grams, butter 20 grams, one cup coffee 350 grams.

Dinner.—Thick pea soup 200 grams, boiled onions 100 grams, boiled sweet potato 250 grams, bread 50 grams, mashed potato 200 grams, butter 20 grams, one cup coffee 350 grams.

Supper.—Sliced banana 150 grams, biscuit 125 grams, fried bacon 20 grams, French fried potato 200 grams, butter 25 grams, one cup tea 350 grams.

Tuesday, March 29, 1904.

Breakfast.—Boiled hominy 175 grams, milk 75 grams, sugar 25 grams, baked potato 250 grams, butter 20 grams, one cup coffee 350 grams.

Dinner.—Hamburg steak with much bread, fat, and onions 125 grams, boiled potato 300 grams, butter 10 grams, one cup coffee 350 grams, bread 35 grams, boiled carrots 125 grams.

Supper.—Tapioca-peach pudding 300 grams, bread 35 grams, Saratoga chips 75 grams, butter 20 grams, jam 75 grams, one cup tea 350 grams.

Wednesday, March 30, 1904.

Breakfast.—Fried hominy 150 grams, syrup 75 grams, butter 10 grams, sliced banana 250 grams, one cup coffee 350 grams.

Dinner.—Codfish-balls (1 part fish, 5 parts potatoes, fried in pork fat) 125 grams, mashed potato 250 grams, stewed tomato 200 grams, bread 35 grams, apple sauce 200 grams, one cup coffee 350 grams.

Supper.—Chopped fresh cabbage with salt, pepper, and vinegar 75 grams, bread 50 grams, butter 20 grams, fried sweet potato 250 grams, cranberry sauce 200 grams, sponge cake 50 grams, one cup tea 350 grams.

Thursday, March 31, 1904.

Breakfast.—Fried Indian meal 100 grams, syrup 75 grams, baked potato 250 grams, one cup coffee 350 grams, butter 20 grams.

Dinner.—Tomato soup, thick, with potatoes and onions boiled together 300 grams, mashed potato 200 grams, scrambled egg 50 grams, bread 50 grams, butter 10 grams, one cup coffee 350 grams.

Supper.—Bread pudding 150 grams, sliced banana 200 grams, fried bacon 20 grams, boiled potato 200 grams, butter 10 grams, one cup tea 350 grams.

Friday, April 1, 1904.

Breakfast.—Fried hominy 150 grams, syrup 75 grams, baked potato 200 grams, butter 20 grams, one cup coffee 350 grams.

Dinner.—Baked spaghetti 250 grams, mashed potato 250 grams, boiled turnip 150 grams, bread 35 grams, butter 10 grams, apple sauce 200 grams, one cup coffee 350 grams.

Supper.—Apple-tapioca pudding 300 grams, fried sweet potato 200 grams, butter 20 grams, jam 100 grams, fried bacon 25 grams, bread 35 grams, one cup tea 350 grams.

NITROGEN BALANCE.—Oakman.

Average Intake.

NITROGEN BALANCE.—Broyles.

NITROGEN BALANCE.—Fritz.

NITROGEN BALANCE.—Loewenthal.

NITROGEN BALANCE.—Cohn.

NITROGEN BALANCE.—Coffman.

NITROGEN BALANCE.—Sliney.

NITROGEN BALANCE.—Steltz.

NITROGEN BALANCE.—Zooman.

NITROGEN BALANCE.—Henderson.

NITROGEN BALANCE.—Morris.

Summary Regarding Nitrogen Requirement.

These results obtained with this body of United States soldiers, living on a prescribed diet and exposed to the stress and strain of military discipline with its attendant duties, together with the gymnastic work and training required each day, confirm in every detail the conclusions arrived at with the preceding group of professional workers. Once accustomed to a more sparing proteid diet, less rich in nitrogen, each one of these subjects had no difficulty in maintaining body-weight on the simpler and lighter food provided. No great difficulty was experienced in establishing a condition of nitrogenous equilibrium with this lowered intake of proteid food, neither was it necessary to increase the amounts of non-nitrogenous foods (fats and carbohydrates) to accomplish this end. The bodies of these men were quite able to adjust themselves to a lowered proteid metabolism, and physiologically speaking, one might well conjecture whether we have not in this condition a nearer approach to the normal and ideal state of the body than when the latter is struggling daily with 118 grams of proteid food, reinforced by fats and carbohydrates correspondingly increased in amount. However this may be, the members of the soldier detail were able to live for five consecutive months with a proteid metabolism corresponding to 7 to 8 grams of nitrogen per day, with maintenance of body-weight and without discomfort or loss of bodily vigor.

It was easy in most instances to prove the establishment of nitrogen equilibrium with a daily intake of 8.5 to 9.5 grams of nitrogen, and with a total fuel value of the daily food equal to 2500 to 2800 calories. In other words, a metabolism of less than 50 grams of proteid per day was quite sufficient for the needs of the body, and a fuel value of 2500 to 2600 calories was ample to meet the requirements of the men under the then existing conditions of bodily and mental activity. Are we not justified, therefore, in again asking the question, why should we hold and teach the doctrine that the healthy adult needs to metabolize 105 grams of proteid food daily? As Voit has well said, the smallest amount of food that will serve to maintain physiological equilibrium and keep up health and strength is the ideal diet. The eleven subjects of this Hospital detachment, who remained throughout the experiment, were apparently able to maintain physiological equilibrium and preserve their health and strength under the conditions of diet as described, thereby demonstrating the possibilities of a physiological economy corresponding to a saving of full fifty per cent or more in proteid food; a saving of possibly great physiological import, to say nothing of the possible economic and sociological importance of the saving. Further, we may add that the minimal proteid requirement as evidenced by the results of these experiments is more than fifty per cent lower than the figures quoted by most physiologists as necessary for the maintenance of life and strength; and we are certainly justified in the additional statement that if the figures obtained in these experiments truly represent the minimal proteid requirement of the men under observation, then this minimal requirement is quite sufficient to meet the physiological needs of the body for an indefinite period.

Physical Condition of the Men.

Recalling the fact that this condition of lowered proteid metabolism was maintained for a period of five months, we may next consider the effect of this changed nutritive condition upon the health and strength of the men. The question of body-weight we have already considered. More pertinent is the question, to how great an extent was the strength and bodily vigor of the men modified by the diminished amount of proteid food? The answer to this question is found in the subjoined report from Dr. William G. Anderson, Director of the Yale University Gymnasium.