During this period of ten months, the body-weight of the subject remained practically constant, or indeed showed a slight gain up to 67 kilograms. All the functions of the body, and the general condition of good health, were in no wise impaired; so that in the words of the subject, the amount of food eaten must have been sufficient for the needs of the body. Somewhat striking is the fact that of the 2309 calories in the daily food, more than one-fourth was derived from the beer consumed daily (1200 c.c.). Also noticeable is the relatively small amount of carbohydrate taken daily, only about one-half the quantity designated by Voit as the average requirement of German laborers. Finally, it is to be observed that during this period of ten months, the daily consumption of food as calculated for a man of 70 kilograms body-weight, based on the actual food consumption of the subject with a weight of 66.5 kilos, was not widely different from our own statement of 60 grams of proteid and 2800 calories. The tendency, however, in Dr. Neumann’s experiment was toward lower fuel values and somewhat higher proteid consumption.

In a second period of 50 days, with a slightly larger daily intake, Dr. Neumann observed that his body was laying by nitrogen, i. e., storing up proteid on a daily diet of 76.5 grams of proteid and with sufficient fat and carbohydrate to furnish a total fuel value of 2658 calories. In the final period of 8 months, the following data were obtained:

AVERAGE DAILY FOOD FOR EIGHT MONTHS

Actually consumed
by the Subject,
71.5 Kilos.		Calculated for a
Body-Weight of
70 Kilos.		Utilizable Food for a
Body-Weight of
70 Kilos.
Proteid76.2 grams74.0 grams61.4 grams
Fat109.0 grams106.1 grams95.5 grams
Carbohydrate168.9 grams164.2 grams152.7 grams
Alcohol5.5 grams5.3 grams4.7 grams
Fuel value2057 calories1999 calories1766 calories

During this period, it is to be noted that the fuel value of the day’s food averaged only 2057 calories, which for a body-weight of 70 kilograms would amount to less than 2000 calories. The proteid consumption, however, was larger than we have found to be necessary for a man of the above weight. Still, the facts are in harmony with the general principle that there is no necessity for a daily intake of food such as common usage dictates, there being obviously a wide difference between a minimal daily consumption of 118 grams of proteid and 3000 or more calories, such as is assumed to be needed by a man of 70 kilos, and 74 grams of proteid with 1999 calories. Under the latter conditions, the subject gained a kilogram in weight during the eight months, while the establishment of nitrogen equilibrium testifies to the now generally accepted view that it is quite possible for the body to establish nitrogen equilibrium at different levels, i. e., with different quantities of proteid food and different fuel values.

The diet made use of by Neumann was a mixed one, containing a great variety of animal and vegetable foods, but withal simple and moderate in quantity. Calculated per kilogram of body-weight, the average consumption of food material per day during the three periods was as indicated in the following table:

DAILY FOOD CONSUMPTION PER KILOGRAM OF WEIGHT

Proteid.Fat.Carbohydrate.Alcohol.Calories
gramsgramsgramsgrams
First Period0.991.334.50.5634.7
Second Period1.102.333.4. .59.7
Third Period1.001.523.40.0728.5

The average of daily food consumption for the total of 746 days was as follows: 74.2 grams proteid, 117 grams fat, 213 grams carbohydrate, and 2367 calories. On such a diet, during this long period, equilibrium was satisfactorily maintained, thereby furnishing additional evidence that quantities of food way below the so-called normal amounts are quite adequate to meet the needs of the body. There is no conflict whatever between these results and our own; they both point in the same general direction. Perhaps the one thing that needs to be again emphasized, however, in view of the low fuel values used by Neumann, is that while they proved quite adequate in his case, the demand in this direction is governed largely by the degree of bodily activity. In fact, Neumann’s results with fuel values are in perfect harmony with the data obtained by us with professional men, but the writer is inclined to believe that for the majority of mankind, with the varying degrees of activity and muscular exertion called for, a somewhat larger number of heat units is desirable, and indeed on many occasions demanded.

Still, it is perfectly obvious that custom has greatly exaggerated the fuel values required in ordinary muscular work, and such results as are here presented tend to emphasize the true relationship between actual requirements and fuel intake. Further, it must not be overlooked that the rate of proteid katabolism is governed in large measure by the amount of non-nitrogenous food, and consequently a too narrow margin in the consumption of the latter will obviously result in a higher rate of proteid exchange. We are inclined to the belief that a satisfactory degree of bodily efficiency is more liable to be maintained with a somewhat larger consumption of carbohydrate food, combined with a reduction in proteid food to a level nearer our own figures. It will be observed that the average amount of carbohydrate taken daily by Neumann, during the 746 days, was only 213 grams, while the daily consumption of fat averaged 117 grams. These figures are interesting and instructive in many ways, especially as indicating the ease with which the body accommodates itself to a relatively low intake of proteid food, combined with a small proportion of starches and sugars. This relationship between carbohydrate and fat might well occur at times as a natural result of personal taste, but as a general rule it is probably better, from the standpoint of digestibility and general availability, for the daily food to contain a larger proportion of carbohydrate.