BODY-WEIGHT. 205 



body-weight is accomplished by excessive exercise. In other words, by 

 keeping the food intake at a constant level and by increasing the 

 demands for energy, the body-weight may be reduced. Fourth, the 

 body-weight may be rapidly lowered for specific short periods by the 

 use of purgatives. Fifth, in addition to exercise and practice, a popular 

 method of reducing weight has been to take very hot baths or to induce 

 profuse perspiration by excessive clothing. Undoubtedly this removes 

 a considerable amount of water from the body, but it has practically no 

 influence upon the organized tissue. 



The method of losing body-weight by changing the character of the 

 diet has, we believe, never been used, although there is no particular 

 reason why this should not be successfully employed. When the 

 carbohydrate in the diet is in large part replaced by fat, it has been 

 quantitatively demonstrated by Benedict and Milner^ that there is a 

 very considerable discharge of water from the body, apparently held by 

 the carbohydrate previously ingested. Undoubtedly this condition 

 is accompanied by a considerable reduction in glycogen content of the 

 body, and glycogen is known to hold considerable quantities of water. 



In order not to complicate the problem by producing excessive loss 

 in weight due to drafts upon body material as the result of excessive 

 muscular exercise, the simpler form of weight reduction resulting from 

 insufficient food, with approximately constant muscular activity, 

 seemed the best procedure. Our problem here, as stated earlier, is a 

 study of the influence of insufficient food and not primarily the study 

 of a loss in weight as a result of excessive exercise. This latter factor 

 presents certain problems that of themselves should receive special 

 experimental treatment. In the first part of the study, a combination 

 of two methods was used with some of our subjects in that the reduc- 

 tion in diet was combined with excessive muscular activity, as these 

 subjects, especially those light in weight, found it difficult to reduce 

 upon the general diet supplied to the squad. Our records show that in 

 certain cases very considerable activity was engaged in to secure the 

 reduction in weight, since all the men were informed at the beginning 

 that they were supposed to reduce their weight 10 or more per cent. 



NORMALITY OF INITIAL BODY-WEIGHTS. 



The initial body-weights of these men are of interest as showing 

 whether they were normal or above or below the normal weight. As 

 would appear natural, it was easier for a man who was above normal to 

 lose weight than a man who was under normal weight. If the selection 

 of subjects could have been made on the body- weight basis and an 

 equal number of men over and under normal weight chosen, the con- 



» Benedict and Milner, U. S. Dept. Agr., Office Exp. Stas. Bui. 175, 1907, p. 225; abstracted by 

 Benedict and Joslin, Carnegie Inst. Wash. Pub. No. 176, 1912, p. 92. 



