306 A YEAR IN SCIENCE 



of the fat and also some of the carbohydrates which 

 we eat are stored away in the body to be kept for 

 future use. 



Quantity and kind of food. It perhaps has never 

 occurred to you that there is a reason, other than taste, 

 why we have certain combinations of foods. For 

 example, why do we use meat, potatoes, other vegeta- 

 bles, and a dessert as the essential parts of a dinner? 

 It is because meat supplies protein and fats ; vegetables, 

 protein but principally carbohydrates ; and dessert, car- 

 bohydrates. All contain mineral salts and water. 

 Together they give us a better balanced ratio of the 

 different foodstuffs than any one food alone would 

 give. Variety in our foods also appeals to the taste. 

 Enjoyment of our foods usually adds to the ease with 

 which they are digested. 



It is difficult to determine how much food we need. 

 The amount varies so much with each individual that 

 we can not make even a general statement of much 

 value. 



Selection of food. Daily in each home a selection of 

 food must be made. What shall determine this selec- 

 tion? Shall we buy the foods which we like the best? 

 Shall we buy the foods which cost the least, or the 

 ones which, according to market prices, are highest 

 priced? It must be apparent to you that not any one 

 of these factors is al'one sufficient to determine this 

 selection. It is not so easily solved that we can merely 

 consult our tastes, or our purses, or the prices which 



