CHAPTER LXVI 



DIETETICS 

 THE CALORIE REQUIREMENT 



In the application of the important facts that have been reviewed in 

 the preceding chapters to the science of dietetics, the question arises as 

 to how we may determine with scientific accuracy just exactly how much 

 food should ~be taken under varying conditions of bodily activity. In a 

 general way, we know that the amount of food that we require to take 

 is proportional to the nature and amount of bodily exercise that is 

 being performed at the time ; and that, if the food supply is inadequate, 

 the work before long will fall off not only in quantity but in quality as 

 well. "Horses (also men) work best when they are well fed, and feed 

 best when they are well worked," is an old adage and one the truth of 

 which can not be overestimated in the consideration of all questions of 

 dietary requirements. An ill-fed beggar will rather suffer from the 

 pain and misery of starvation than attempt to perform a piece of work 

 that the well-meaning housewife bargains should be done before she 

 gives him a meal. The spirit may be willing but the flesh is weak. If he 

 could be trusted, he should be fed first and worked afterwards. Besides 

 the amount of work, two other factors are well known to influence the 

 demand for food namely, growth and climate. A young, growing boy 

 will often demand as much if not more food than would appear to be 

 his proper share, from a comparison of his body weight with that of 

 his seniors; and, other things being equal, it is well knoAvn that we are 

 inclined to eat much more heartily of food during the cold days of 

 winter than during the sultry days of July and August. 



That we know these facts in a general way, indicates that the first 

 step to take in the exact determination of dietetic requirements is to 

 find out how mueh energy the body expends under varying conditions 

 of activity. This, as we have seen, may be done by having the person 

 live for some time in a respiration calorimeter, so that we may measure 

 the calorie output. To the conclusions drawn from results of observa- 

 tions made under such artificial and unusual conditions of living, the 

 objection might, however, quite justly be raised that they need not 

 apply to persons going about their ordinary routine of life. To meet 



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