Comparison of these figures shows that six of the men were practically of the same body-weight at the close of the experiment as at the beginning. Of the others, Oakman, Fritz, Cohn, and Bates lost somewhat. Bates, however, was quite stout, and the work in the gymnasium as well as the change of diet tended to reduce his weight. In fact, with the possible exception of Oakman, the slight loss of weight these latter men underwent was a distinct gain to their bodily condition. The most significant feature, however, is to be found on scrutiny of the tables of results for each man, where is seen the body-weight for each day of the six months. Here it will be noticed that, as the experiment progressed, there was, as a rule, a tendency for the body-weight to increase; this was followed by a decline, after which the weight remained practically stationary. This is well illustrated in Oakman’s case. Starting with a body-weight of 66.7 kilos on October 4, he reached 67.6 kilos on November 29, then declining in weight to 62.3 on January 18, after which he remained practically stationary, or varied only within narrow limits.
Finally, it should be said that the low proteid metabolism on which these men were apparently maintaining body-weight was not associated with any increase of non-nitrogenous food. At no time did the fuel value of the daily food reach 3000 calories; in fact, about January 12 the average fuel value of the food was only a little over 2000 calories per day.
First Nitrogen Balance.
Early in January, the body-weight of the men having become practically stationary and the proteid metabolism, as measured by the output of metabolized nitrogen, having been reduced to a low level, an attempt was made to see if the men were truly in a condition of nitrogenous equilibrium. A six-day period was used, during which all the food for each meal was carefully analyzed, the nitrogen in every sample of food being determined in duplicate by the Kjeldahl-Gunning process. The fæces of the period were separated by lampblack, given at appropriate times in gelatin capsules, and all necessary precautions observed to insure an accurate nitrogen balance. The accompanying tables of results give all the necessary data.
The average nitrogen intake per day was 8.23 grams, and the average fuel value of the food per day was 2078 calories. These are the figures for Oakman. With some of the other men there were slight variations from these figures, as shown in the tables—owing to slight variations in diet. Without exception, all the men showed a minus balance, indicating that on this diet the body was losing nitrogen. In other words, the diet as a whole was insufficient for the needs of the body in every case. Whether this was due to lack of sufficient proteid or to an insufficient amount of fat and carbohydrate, i. e., a too low fuel value, cannot be said definitely, but there is every reason to believe that the amount of non-nitrogenous food was insufficient to furnish the requisite fuel value, and consequently body proteid was drawn upon to supply the deficiency. The loss of nitrogen to the body per day varied as a rule from 0.5 to 2.0 grams. In one case only, viz., Broyles, was there a close approach to a balance. In his case there was a minus balance of only 0.12 gram of nitrogen per day.
The average daily output of nitrogen through the urine for this six-days period (Oakman’s case) was 7.52 grams.
FRITZ
Photograph taken at the close of the experiment.