Variations in Metabolism. 231 



Variations in Metabolism Due to Variations in Physical 

 Characteristics, Age and Muscular Activity. 



variations in metabolism due to weight, height and age. 



As early as the investigations of Andral and Gavarret, 1 the differences in 

 metabolism of individuals with marked variations in body characteristics, es- 

 pecially in regard to size, weight, height, and age, were considered possible. 

 The most extended investigations of this kind are those of Sonden and Tiger- 

 stedt 2 with the large respiration chamber in Stockholm, and those of Magnus- 

 Levy and Falk 3 with the Zuntz apparatus. These two investigations, primarily 

 undertaken with the idea of studying the effect on metabolism of variations in 

 age and sex, must still remain as our basis for these comparisons, but in the 

 experiments made with the respiration calorimeter and published in this and 

 previous reports, certain further evidence is at hand for studying the influence 

 of variations in body condition on metabolism. No general investigation with 

 this particular point in view was undertaken, but the experiments as selected 

 from the list of 55 men experimented with enable us to make certain compari- 

 sons and deductions. 



One of the first difficulties experienced is the proper classification of the men 

 and the application of some popular term that will give a general idea as to the 

 physical condition of these individuals. In certain cases the distinction between 

 the men is very marked; thus with the professional athlete, 1ST. B., there is no 

 question that there was very little, if any, superfluous fat. On the other hand, 

 the subject, H. F., although of distinctly athletic proportions and build, and a 

 man of wonderful strength, nevertheless had a distinct layer of abdominal fat 

 that would exclude him from being classified as an athlete, and from the body- 

 weight and height we class him herewith among the short, fat men. The 

 subject A. L. L., however, with identically the same body-weight as H. F., and, 

 indeed, even less in height, is grouped as a short man, for a physical exami- 

 nation of this subject showed very little superfluous fat and he was distinctly 

 of the athletic type. 



It is evident that a classification involving so much personal opinion and 

 judgment can be considered as only approximate and it is at best distinctly 

 unsatisfactory. Until some uniform method is adopted of expressing bodv- 

 weight and body measurements in such a way as will classify them in well- 

 defined groups, we have no other alternative than to be strongly guided by 

 personal impression. The possibility has been considered of photographing the 

 body in profile in two positions at right angles to each other, but the investiga- 

 tion did not seem to warrant making such elaborate attempts to describe the 

 body condition; indeed, it would now be impossible to secure accurate data, 

 since a number of these subjects had not reached maturity at the time of the 



1 Andral and Gavarret, loc. cit. 



2 Sonden and Tigerstedt, loc. cit. 



3 Magnus-Levy and Falk, loc. cit. 



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