We have presented in table 36 the probable caloric requirements of these men for maintenance at the lower weight-levels. These values, given in round numbers, range from a minimum of 1,600 calories with Kon, Tom and Pec to a maximum of 2,500 calories with Can. At first sight Can's requirement appears inconsistent, for although Can was the heaviest man in the group, he was by no means so active athletically as some of the other men. The man who was probably the most active (Pea) shows, however, a maintenance requirement of 2,400 calories. To those of us who know the men individually, the most surprising figures in the table are the low values with Pec and Kon. With Kon, it will be remembered, somewhat unsatisfactory figures were obtained, and we are uncertain as to whether the energy intake cited is the actual maintenance level. On the other hand, the picture for Pec is reasonably clear. It is not impossible that the latter's age (44 years) may have had an effect upon the energy requirement, for we know that the older a man is the greater the tendency is towards a lower basal metabolism. Averaging the values for the 12 men, we have an average value of 1,967 net calories for maintenance at the lower weight-level, i. e., in round numbers, 1,950 net calories.

Table 36. - Net Energy Required For Weight Maintenance At Low Weight-Level - Squad A

[Derived from body-weight curves. See figs. 57 to 68].

The significance of this low figure is perhaps best emphasized when one refers to the probable caloric requirement for weight maintenance prior to dietetic restriction. For this we have two sources of information: (1) the nitrogen balance (see tables 46 to 58, pp. 312 to 341) and (2 )the summary in table 35 of the net caloric intake in the so-called "normal diet" from October 1 to 4; this intake averaged not far from 3,100 calories. If we examine the nitrogen in the food for these days, also given in table 35, it is clear that the amounts of food taken by these men were not the amounts normally taken by them. In the first place, they could not consciously have selected so uniform a nitrogen intake as they actually showed. In the second place, Chef Hall, who was very observant, pointed out to us that the men in Squad A in the normal-diet period of October 1 to 4 showed less appetite for their food than previously. On the first return of the college students in the autumn, they usually eat with great appetite, as the food is new to them and they enjoy it very much. There is then a period, usually of a week or ten days, when there seems to be a distinct slackening in the appetite, this actually having an effect upon the purchase and preparation of food in the kitchen. Subsequently they return to their normal appetite and food intake. It was our misfortune to have selected this period of low appetite in which to study the normal diet of these men. Mr. Hall's observation seems to be fully verified by the results of a study with a control squad on normal diet November 20 to 24, which are given in table 32 (p. 268). On 5 days 12 men showed an average energy intake of 4,104 gross calories per day. Deducting approximately 8 per cent, or 328 calories, for the energy outgo in urine and feces, we have 3,776 calories as the average net calories available for this period.

Diet and Control Squads and Investigators, International Young Men's Christian Association College, Springfield, Massachusetts, January 11, 1918.

Control Squad (B) top row, standing: Livingstone, Williams, Kimball, Thompson, Long, Hammond, Van Wagner, Hartshorn, Howland, Fisher, Snell, Schrack. (McMichael absent.) Low-diet Squad (A), middle row, standing: Gullickson, Gardner, Moyer, Canfield, Veal, Beckham, Peabody, Montague, Brown. (Spencer, Tompkins, and Kontner absent.) Investigators, sitting: Emmes, Miles, Smith, Both, Benedict, Berry, Johnson, Fox.

An inspection of the data for the calories in feces and urine for the first three days of October in the several balance tables (pp. 312 to 341) shows that the estimate of 8 per cent for outgo in urine and feces is not unreasonable. This would imply, therefore, that the normal food requirement of the average undergraduate student in the Springfield Y. M. C. A. College was, during the period of November 20 to 24, when this control squad was studied, nearer 3,800 calories than the 3,100 calories shown for Squad A in table 35. On the assumption that the normal energy requirement is 3,800 calories, the average caloric requirement of 1,950 calories found to hold the body-weight at the lower level was thus a little over one-half of the normal requirement; in other words, the caloric requirement had been lowered nearly one-half. Using the level of 3,100 calories actually found with Squad A from October 1 to 4, we see that the dietetic restrictions have lowered the caloric requirement 1,150 calories, or a little more than one-third. Even if we raise slightly the caloric requirement at the lower level of body-weight, we would still have reduced the normal requirement of 3,100 calories not less than one-third. It must again be pointed out, however, that body-weight is a very uncertain criterion of the condition of the body reserves. A period of two weeks is too short to obtain results of definite significance. In this particular case, however, with the majority of our subjects two periods separated by nearly a month or six weeks indicated approximately the same uniformity of weight-level with the same caloric intake; hence, we believe we are more justified in using these short periods of constancy in body-weight as a measure of maintenance than if we had but one period. The general conclusion can be drawn, therefore, that using the constancy in body-weight at the lower level as a criterion, the food requirements are approximately one-third less than they are at the higher level.