| Morris | 7.03 | ⎫ | = 7.80 grams Nitrogen as the grand average. |
| Steltz | 7.13 | ⎪ | |
| Broyles | 7.26 | ⎪ | |
| Loewenthal | 7.38 | ⎪ | |
| Oakman | 7.42 | ⎪ | |
| Fritz | 7.84 | ⎬ | |
| Cohn | 8.05 | ⎪ | |
| Coffman | 8.17 | ⎪ | |
| Zooman | 8.25 | ⎪ | |
| Sliney | 8.39 | ⎪ | |
| Henderson | 8.91 | ⎭ | |
| Bates | 8.08 | — | Oct. 27-Feb. 11. |
| Davis | 8.61 | — | Oct. 26-Jan. 12. |
The figures given show an astonishingly low proteid metabolism for the five months’ period; 7.5 grams of nitrogen in the day’s urine correspond to 46.8 grams of proteid metabolized, while 8.5 grams of nitrogen mean the metabolism of 53.1 grams of proteid. In other words, all of these men during a period of five months practically averaged a daily output of nitrogen through the kidneys corresponding to the metabolism of less than one-half the 105 grams of absorbable proteid called for by the so-called standard diets. Further, close scrutiny of the results in the individual tables shows that during many weeks much lower results were obtained than is indicated by the general averages.
Just here emphasis should be laid upon one fact, doubtless of primary importance in any modification of the rate or extent of metabolism in any individual, viz., that in this experiment the daily diet was prescribed, thereby taking from the individual freedom of choice in the selection of food. The writer has no question in his own mind that an intelligent choice of food, coupled with the satisfying of a natural or acquired appetite in moderation, will lead to better results than any system of prescription as to what shall be eaten each day and in what quantity. Still, this is the method necessarily made use of in the present experiment, the writer having prescribed the character and amount of each meal throughout the entire six months’ period, with due regard, of course, to the expressed likes and dislikes of the men.
One feature in the diet compelled by the circumstances of the case also needs to be referred to, namely, the necessity of keeping the men thoroughly satisfied, so that there should be no feeling of hunger, no craving for food. With a person interested in the experiment and desirous of ascertaining the effect of a low nitrogen intake, there would naturally be a willingness to endure, if necessary, for a time some personal discomfort; but with this detail of the United States Army it could not be expected that the men would remain satisfied if they were compelled to undergo the pangs of hunger even for a day or two. Consequently, it was necessary in prescribing the daily diet to see that the quantity of the food was such as to completely satisfy the appetite. This necessitated the use of considerable bulky food of low fuel, and low nitrogen, value. In this way only was it feasible to reduce the nitrogen intake, as well as the fuel value of the food, to the desired level. Practically during the entire six months’ period, with the possible exception of a few days, the men were given sufficient food to completely satisfy their appetites. Throughout the entire period of the experiment, the men all manifested a keen appetite and utilized their food to good advantage, with establishment of the nitrogen metabolism indicated by the foregoing results.
Still confining our attention to the average results regarding nitrogen excretion, we may ask the question, what was the excretion of metabolized nitrogen per kilo of body-weight in the different individuals? This is easily calculated and the data are shown in the following table, in which the figures standing for body-weight are either the data for the month of April, 1904, or else the average between the October and April weights, as in those cases where the body-weight fell off during the experiment.
| Body-weight. | Average daily Output of Nitrogen. November-April. | Metabolized Nitrogen per kilo Body-weight. | |
|---|---|---|---|
| kilos | grams | gram | |
| Fritz | 74.0 | 7.84 | 0.106 |
| Oakman | 64.0 | 7.42 | 0.116 |
| Bates | 68.0 | 8.08 | 0.118 |
| Morris | 59.0 | 7.03 | 0.119 |
| Broyles | 60.0 | 7.26 | 0.120 |
| Henderson | 71.0 | 8.91 | 0.125 |
| Loewenthal | 59.0 | 7.38 | 0.125 |
| Cohn | 63.5 | 8.05 | 0.126 |
| Steltz | 53.0 | 7.13 | 0.134 |
| Sliney | 60.0 | 8.39 | 0.138 |
| Coffman | 58.0 | 8.17 | 0.140 |
| Davis | 58.0 | 8.61 | 0.148 |
| Zooman | 55.0 | 8.25 | 0.150 |
Scrutiny of these results shows that the daily excretion of metabolized nitrogen ranged in this period of five months from 0.106 gram per kilo of body-weight up to 0.150 gram per kilo of body-weight. Since these men were on essentially the same diet, it is obvious that there were some peculiarities, or personal idiosyncrasies, that tended to modify the exact extent of proteid metabolism, and in some cases at least constituted a more potent factor than body-weight in determining the rate of metabolism. This fact is clearly emphasized in the case of Morris, who, with a body-weight of 59 kilos, showed a proteid metabolism equivalent to only 7.03 grams of nitrogen per day, and Coffman, who, with a body-weight of 58 kilos, showed under the same conditions an average excretion of 8.17 grams of nitrogen per day.
What was the effect of this lowered proteid metabolism upon the bodily condition, especially body-weight? To answer this question the weights of the men are given in the following table, the one column of figures showing the body-weight at the commencement of the experiment, the other column showing the weight at the close of the experiment.
TABLE OF BODY-WEIGHTS.
| October, 1903. | April, 1904. | ||
|---|---|---|---|
| kilos | kilos | ||
| Steltz | 52.3 | 53.0 | |
| Zooman | 54.0 | 55.0 | |
| Coffman | 59.1 | 58.0 | |
| Morris | 59.2 | 59.0 | |
| Broyles | 59.4 | 61.0 | |
| Loewenthal | 60.1 | 59.0 | |
| Sliney | 61.3 | 60.6 | |
| Cohn | 65.0 | 62.6 | |
| Oakman | 66.7 | 62.1 | |
| Henderson | 71.3 | 71.0 | |
| Fritz | 76.0 | 72.6 | |
| Bates | 72.7 | 64.3 | February |
| Davis | 59.3 | 57.2 | January |