IN RELATION TO THE WAR. 483 



fully weighed, sampled, and analyzed for the individual men. It is 

 thus possible for us to measure the complete intake of protein and 

 calories. The urine was collected throughout the entire time, and 

 the feces at frequent intervals. It is a tribute to the painstaking 

 and conscientious cooperation of these men that throughout the 

 entire period of four months the urine was rarely lost. We thus 

 have complete data for striking a balance between the nitrogen in 

 the food and the nitrogen in urine and feces. 



Advantage was taken of each bi-weekly visit of the separate 

 squads to the Laboratory in Boston to put them through 17 psycho- 

 physiological tests. Although it was rather difficult to secure much 

 evidence of introspection without the danger of sugges'tion, careful 

 records of all the relevant observations on introspection were made. 



The most important scientific findings may be summed up as 

 follows : 



1. A gradual reduction in weight to a point 12 per cent, below the 

 initial weight took place during a period of from 3 to 10 weeks, 

 with low calories and a moderate amount of protein in the food 

 intake. The normal demand of the men prior to the dietetic altera- 

 tion ranged from 3,200 to 3,600 net calories. One squad of 12 men 

 subsisted for three weeks on 1,400 net calories without special dis- 

 turbance. 



2. After the loss in weight of 12 per cent, had been reached, the 

 net calories required to maintain this weight averaged about 2,300, 

 or approximately one third less than the original amount required. 



3. At the end of the reduction in weight the actual heat output 

 during the hours of sleep, as computed by indirect calorimetry, was 

 approximately one fourth less than normal, thus giving a rough con- 

 firmation of the lowered number of calories found by actual meas- 

 urement of the food intake. That there was no pronounced seasonal 

 variation in metabolism was shown by the uniformity of the metab- 

 olic level of the control squad (Squad B). 



4. The heat output by indirect calorimetry per kilogram of body- 

 weight and per square meter of body surface was essentially 18 per 

 cent, lower than at the beginning of the study. 



5. Throughout the period of loss in weight and for some time 

 subsequent thereto, there was a pronounced loss of body nitrogen. 



