DIETS. 271 



with a group of 12 men the body-weight, carefully measured over a 

 period of several days, if not weeks, could be taken as an index of 

 caloric requirement for weight maintenance. The total amount of 

 calories required to hold the body-weight at maintenance level would 

 thus be the amount actually required for the daily activity of this 

 group of men. Had there been but one subject, we could have ap- 

 portioned the total daily calories in one meal or one allotment and 

 allowed the subject to eat as freely as he chose throughout the day, 

 either in three meals or in more, if he wished. With certain members 

 of our squad this plan might have been very successful, for not in- 

 frequently the desire to eat away from the table was disquietingly 

 strong. For a group of men, however, this method of procedure 

 would give a less strict control. We therefore considered it best for 

 the men to eat at the table under the supervision of a member of the 

 Laboratory staff. 



The caloric allotment was not regular from day to day. One might 

 ask why a definite number of calories was not assigned each day, for 

 theoretically this would have been the proper procedure. Practically 

 the caloric allotment was in large part decided by the character of 

 the food served in the regular mess hall by the chef on that particular 

 day. If the food was especially fat-rich, the energy was liable to be 

 large; if it was fat-poor, the energy was low, for we usually attempted 

 to serve small portions, irrespective of the character of the food itself. 

 Consequently, an examination of the tables giving the daily intakes of 

 nitrogen and energy shows relatively large fluctuations from day to day. 

 On the other hand uniform average levels for the intake of energy may 

 be found with practically all the subjects for periods of weeks, as shown 

 in nearly all the tables. These average levels have been blocked in on 

 the body-weight curves (see figs. 57 to 68), the energy intake being 

 in this case the net calories — that is, the caloric intake less the 

 calories of urine and feces. 



An inspection of these curves shows that the net calories during 

 comparable periods of time remained fairly uniform from individual to 

 individual. Obviously the large men as well as the more active men 

 required more calories. While there were wide fluctuations from day 

 to day, the averages for a week or ten days are alone to be considered. 

 This method of allowing a reasonably free food intake, without stipu- 

 lation as to the exact number of calories or grams of nitrogen for each 

 day, made it much easier to use the food ordinarily served in the dining 

 room and thus provide the necessary variety. We still see no reason 

 for altering this procedure. 



In summation, therefore, we should state that the diets given to 

 these subjects were, so far as character is concerned, those ordinarily 

 employed in the dining-room. A great variety of foods was sup- 

 plied. No special dietetic control, such as special amounts of pro- 



