FOOD AND DIET. 



379 



It will be observed that the animal foods are especially rich in protein 

 and fat, and in ordinary life most of the necessary protein is taken in 

 the form of beef, mutton, and eggs. Vegetable foods, on the other 

 hand, are the chief source of carbohydrates, and the latter substances 

 in a dietary are usually derived from bread, rice, and potatoes. Some 

 vegetable foods contain a considerable amount of protein, but the 

 vegetable proteins are not so easily and completely digested and 

 assimilated as those contained in animal food, and therefore from a 

 physiological point of view it is more wasteful to obtain the necessary 

 protein from vegetable than from animal sources. Moreover, in order 

 to get the requisite amount of protein, a vegetable diet must be con- 

 siderably more bulky than a diet which is partly composed of animal 

 substances. 



If the amounts of the alimentary principles required daily be 

 taken as : 



Protein. . . . .120 grams 

 Carbohydrate . . . 500 ,, 

 Fat . . . . 60 



Salts 30 



a dietary may be constructed from the table of food-stuffs as follows : 



Rice, which is included in this dietary, contains 76 per cent, of starch 

 and minute quantities of fat and protein. It will be observed that the 

 salt content of the diet is deficient, and would have to be supplemented 

 by means of common salt. 



