72 



THE PROTEIN ELEMENT IN NUTRITION 



us examine the results that have been obtained with dietaries 

 peculiar to Japan, India, and the tropics. 



Oshima,* in his digest of Japanese investigation on the nutri- 

 tion of man, gives the results of a large number of dietary studies. 

 Although these do not deal with the poorer classes or rural 

 population to any great extent, he has succeeded in collecting 

 a valuable amount of information on the foodstuffs and dietaries 

 of the Japanese. He shows that soldiers and sailors, and those 

 in comfortable circumstances in other classes, including pro- 

 fessional and business men and students, are in general well 

 nourished. The amounts of protein and energy in the diet of 

 these classes compare well with those in the diet of people under 

 similar circumstances in Europe and America, especially when 

 allowance is made for the smaller average weight of the Japanese. 



The dietary studies with the poorer classes, including em- 

 ployees, prisoners, military colonists, and investigations on purely 

 vegetarian diets, show that the amount of protein is about 

 60 grammes per man daily and the energy about 2,500 calories. 

 The average body weight of the Japanese is computed to be 

 about 54 kilos ; this would mean a metabolism of 1-111 grammes 

 protein or 0-177 grammes of nitrogen per kilo of body weight, 

 as contrasted with 0-224 to 0-27 grammes nitrogen per kilo of 

 body weight in Europeans and Americans. 



The amount of animal food in the Japanese dietaries is much 

 less than in the average American dietary. A comparison is 

 given of the total protein derived from an animal and other 

 sources in 25 Japanese and 185 American studies : 



A special characteristic of the Japanese diet, and also, to 

 some extent, of Indian dietaries, is that the amount of fat is very 

 low ; in Japan, also, dairy products are practically unknown. 

 In connection with the commonly accepted idea that the Japanese 

 are vegetarians, it is interesting to note that Oshima comes to 

 much the same conclusion as that arrived at in discussing the 



* Oshima, U.S. Department of Agriculture, Bulletin No. 159. 



