A STUDY OF FOODS 57 



without any loss of weight, when they had become accus- 

 tomed to taking less than half their ordinary amount of food. 

 In several instances rheumatism, biliousness, and other 

 derangements of the body were cured by this restricted diet. 

 " There is no question, in view of our results," says Professor 

 Chittenden, that people ordinarily consume much more 

 proteid food than there is any real physiological necessity 

 for, and it is more than probable that this excess of food is 

 in the long run detrimental to health, weakening rather than 

 strengthening the body, and defeating the very objects aimed 

 at." 



Necessity for a Mixed Diet. By comparing the proportions 

 of the nutrients suggested for the daily diet with the com- 

 position of the various foods given in Fig. 22, one sees that 

 in none of them are the nutrients in the right proportions. 

 Cow's milk comes the nearest to being a perfect food, but its 

 percentage of carbohydrates is too small; if we were to feed 

 upon meat alone, we should get too large an amount of 

 proteid s; while most of the vegetable foods supply an ex- 

 cessive amount of carbohydrates. Hence, a well-balanced 

 diet should consist of a mixture of many kinds of foods, a 

 conclusion that agrees with our everyday experience. Vege- 

 tarians may be right in their contention that all the nutritive 

 elements of food are found in vegetables, but the great pro- 

 portion of the human race doubtless secure a far more 

 healthful diet by combining the animal proteids and fats 

 with the carbohydrates furnished by plants. 



7. FOOD ECONOMY 1 



Importance of Food Economy. It is said that in a large 

 proportion of American families more than half of the total 

 income is spent for food, and that rent, fuel, clothing, and 

 all other expenses must come from the remainder; hence 

 the importance of the study of food economy. The average 

 American, however, is far from economical in the matter of 



1 See "Laboratory Exercises," No. 16, B. 



