CHAPTER XXVIII 

 HYGIENIC ASPECTS OF NUTRITION 



287. The purpose of food. Many people do not consider why 

 they take food into their bodies. Doubtless, if asked to give 

 an immediate answer to the question as to why they eat, many 

 would say that it is to satisfy hunger. In a way such an 

 answer would be correct, but it would be superficial. Indeed, 

 if that were the only reason, it would not be worth while to 

 expend all the time and trouble that we do about our eating. 

 One may discipline himself in a few days, as has often been 

 done by men who have fasted, to such an extent that hunger 

 no longer troubles him seriously. If this were continued, death 

 would ensue, though the person, it is said, might not be con- 

 scious of hunger for some time prior to his death. 



We eat in order that the body may be nourished, in order 

 that growth may take place, in order that waste protoplasm 

 may be replenished above all, in order that energy may be 

 brought into the body and used in doing its work, whether it 

 is the beating of the heart or the changes in the brain tissues 

 which make thought possible. Growth and replenishment of 

 protoplasm and the release and use of energy are therefore 

 the real purposes of nutrition. 



288. The body a machine. There are many simple machines, 

 as a pair of scissors or a pocketknife, the structure and oper- 

 ation of which are quite easily understood. Few people, how- 

 ever, really understand how a locomotive operates, though most 

 people are interested in learning about it. A smaller number 

 of people know much about the operation of the human body. 

 It is a machine that is far more complex than the locomotive, 

 and a machine which each of us must have a hand in running. 



