CHAP, in THE THEOKY OF HUMAN NUTKITION 91 



easier to obtain, are regarded as less valuable, since such persons 

 cannot choose their food freely, and the objection may consequently 

 be raised that their diet is arranged according to the theories of 

 the individual at the head of such communities or institutions. 



Before proceeding to a minute criticism of the scientific value 

 of this statistical method, let us examine the results obtained by 

 it as regards the definition of the normal human diet. 



Voit, in his famous lecture at Munich in 1875 before the 

 Public Health Congress, proposed 118 grms. of protein, 56 of fat, 

 and 500 of carbohydrate as the normal diet of an average working 

 man ; this calculation was based on the results of a large number 

 of observations. He regarded as an average working man a 

 robust man weighing 67 kgrms., able to accomplish daily in nine 

 to ten hours a considerably larger amount of muscular work 

 than a tailor, though less than a blacksmith, and much the same 

 amount as a mason or a carpenter. 



The heat value of such a diet amounts to 3055 calories, which, 

 if we deduct the heat of combustion of the faeces, estimated by 

 Tigerstedt at 10 per cent, gives a total of 2749 calories. 



In the case of men doing heavier work, Voit finds that the 

 daily requirements are greater, i.e. 145 grms. of protein, 160 of 

 fat, and 450 of carbohydrate. This diet represents a total value 

 of 3370 calories. 



Atwater (1902-3), as the result of still more numerous 

 observations, estimated the normal diet of workmen doing a 

 moderate amount of work at 125 grms. of protein, together with 

 such quantities of fat and carbohydrate as would raise the total 

 heat value to 3500 calories. He considered that workmen 

 engaged in harder work required a diet of 150 grms. of protein, 

 and an amount of fat and carbohydrate sufficient to raise the 

 total to 4500 calories. 



These approximate data are generally accepted by physiologists 

 and hygienists. Tigerstedt, one of the greatest authorities, and 

 the most recent writer on the subject (1909), considers the number 

 of calories represented by Voit's average diet too low, and 

 advocates that of Atwater. He notes that the dietary established 

 in 1891 in the Swedish prisons for those condemned to penal 

 servitude corresponded closely to what Voit considered a normal 

 average, but the convicts were allowed to spend part of their 

 weekly earnings in supplementing the ordinary diet. Later, 

 owing to various prison regulations, the convicts were almost 

 entirely forbidden to spend their earnings in this way, but after 

 a short time this prohibition had to be removed, the ordinary 

 diet having been proved to be inadequate. It would be more 

 accurate to say that the complaints of the prisoners were accepted 

 as proof of the insufficiency of the diet. 



With regard to the food requirements of the average working 



