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THE VITAL PROCESSES 



While there is probably no necessity for the healthy 

 individual's taking his proteid, fat, and carbohydrate in 

 exact proportions (if the proportions best suited to his body 

 were known), the fact needs to be emphasized that pro- 

 teids, although absolutely necessary, should form but a 

 small part (not over one fifth) of the daily bill of fare. In 

 recognition of this fact is involved a principle of health 

 and also one of economy. The proteids, especially those 

 in meats, are the most expensive of the nutrients, whereas 

 the carbohydrates, which should form the greater bulk of 

 one's food, are the least expensive. 



Effects of a One-sided Diet. The plan of the body is 

 such as to require a mixed diet, and all of the great classes 

 of nutrients are necessary. If one could subsist on any 

 single class, it would be proteids, for proteids are able both 

 to rebuild tissue and to supply energy. But if proteids 

 are eaten much in excess of the body's need for rebuilding 

 the tissues, and this excess is oxidized for supplying energy, 

 a strain is thrown upon the organs of excretion, because 

 of the increase in the wastes. Not only is there danger ol 

 overworking certain of these organs (the liver and kidneys), 

 but the wastes may linger too long in the body, causing 

 disorder and laying the foundation for disease. On the 

 other hand, if an insufficient amount of proteid is taken, 

 the tissues are improperly nourished, and one is unable to 

 exert his usual strength. What is true of the proteids is 

 true, though in a different way, of the other great classes 

 of foods. A diet which is lacking in proteid, carbohydrate, 

 or fat, or which has any one of them in excess, is not 

 adapted to the requirements of the body. 



Composition of the Food Materials. One who intelli- 

 gently provides the daily bill of fare must have some 

 knowledge of the nature and quantity of the nutrients 



