PURPOSE AND PLAN OF RESEARCH. 37 



food is adjusted in general to the demand of the body for fuel. This is 

 best shown by the fact that, after maturity, the body-weight for the 

 majority of individuals does not change widely for periods of years. 

 Since the law of the conservation of energy obtains in the human body, 

 the food intake thus corresponds on the average to the demands for 

 energy. When food is absorbed, it can be disposed of in but two ways, 

 either burned or stored as fat. If stored as fat, the weight would in- 

 crease; if burned, the metabolism has been increased. Since the basal 

 metaboUsm of an individual remains reasonably constant, any great 

 increase in metabolism must be due to an increase in activity, ^. e., 

 muscular work. Consequently experimental evidence points to the 

 fact that the ordinary dietetic habits of a community are usually 

 adjusted to its needs for metabolic level and muscular activity. 



Recently the food stringency in Germany has thrown new light upon 

 the possibilities of establishing lower nutritional levels by reducing the 

 intake of food and lowering the body-weight. 



HISTORY OF INCEPTION OF RESEARCH. 



In the spring of 1917 it was the good fortune of one of us to have a 

 long conference in Philadelphia with Professor Alonzo E. Taylor, who 

 had but recently returned from Germany. Professor Taylor was thor- 

 oughly conversant with the food situation in that country, had dis- 

 cussed the subject in extenso with eminent German physiologists, and 

 hence was specially provided with information as to the present die- 

 tetic habits of both the civihan population and the army in Germany. 



According to Professor Taylor, it would appear from the ration cards 

 and from the computations of the best hygienic and dietetic experts that 

 the German civilian population were securing not more than 1,800 

 calories per man per day. The German army ration approximated 

 3,200 calories per day. In an article laying particular emphasis upon 

 the role of acid and alkali-forming ingredients in the diet, Ragnar- 

 Berg^ gives a tabular presentation of the army ration in Germany as 

 well as that of the hard worker and the civilian. These values bear 

 out quite closely Professor Taylor's estimates. Aside from results 

 obtained in the study made by Loewy and Zuntz,^ and Jansen,^ 

 previously referred to, and with which we were unfortunately not 

 earlier acquainted, the reports from Germany lack that scientific 

 verification that one would prefer to have, but the possible adjust- 

 ment to a lower nutritional level seems sufficiently estabUshed to be 

 accepted as highly probable. The fact is established, however, that 

 as a result of this reduction in diet, the obese are now rarely seen in 

 Germany, that the German civilians have lost considerably in body- 



^ The original place of publication in Germany is not given, but the article is abstracted in the 



Bull, de la Soc. Sci. Hyg. Aliment., 1918, 5, p. 652. 

 * Loewy and Zuntz, Berl. klin. Wochenschr., 1916, 53, p. 825. 

 'Jansen, Deutsch. Archiv. f. klin. Med., 1917, 124, p. 1. ' 



