FOOD 



2211 



FOOD 



of water one degree centigrade; this is practi- 

 cally the amount necessary to heat one pound 

 of water four degrees Fahrenheit. Careful ex- 

 periments have determined the fuel values of 

 the different classes of foods to be as follows: 



Protein, 4 calories per gram, or 1,820 calories 

 per pound. 



Fats, 9 calories per gram, or 4,040 calories per 

 pound. 



Carbohydrates, 4 calories per gram, or 1,820 

 calories per pound. 



All nutritious foods are fairly good fuels, 

 but not nearly so good as pure fats. One can 

 readily see why people living in a temperate 

 climate eat more fat in winter than in sum- 

 mer, why the Eskimo drinks his blubber with 

 relish, and why people of the tropics eat little 

 or no fat. 



Digestibility of Food. "We live not upon 

 what we eat, but upon what we digest." Food 

 must undergo a number of chemical changes 

 before it becomes suitable to nourish the body. 

 Digestibility is an important consideration in 

 selecting food. This means not only the ease 

 with which a given article of food is digested, 

 but also the amount of nutriment it will yield. 

 The time required for digestion depends upon 

 the class of food, the quantity and the condi- 

 tion of the stomach. The following table, 

 based upon investigations made by the United 

 States Department of Agriculture, published 

 in Bulletin 142, contains valuable information 

 concerning various articles of food ordinarily 

 used in a mixed diet: 



health and maintain his strength much better 

 on a mixed diet. All the organs and tissues 

 of the body contain proteins; proteins are the 

 only substances that can supply nitrogen, and 

 comparatively few vegetable foods are rich in 

 proteins. Nine-tenths of the fat in an ordinary 

 diet is supplied by animal foods, and about 

 nine-tenths of the starch and sugar by vege- 

 table foods. Since small quantities of mineral 

 matter are found in all foods, a mixed diet 

 supplies the body's needs. 



Quantity of Food. The quantity of food 

 needed depends upon a number of conditions. 

 These are: 



Sex. Men, being larger and more active 

 than women, require more food. The average 

 woman eats about four-fifths as much as the 

 average man. 



Age. A growing child requires proportion- 

 ately more food than an adult. Boys and girls 

 over fourteen eat nearly as much as adults of 

 the same sex. An aged person requires less 

 food than one in middle life. After the age 

 of sixty the diet may be reduced about one- 

 tenth for every ten years of age. 



Occupation. A man engaged in manual labor 

 in the open air, as a lumberman or stonecutter, 

 for instance, requires more food than a clerk 

 or one working at a desk. 



Climate. People living in cold climates re- 

 quire more food than those living in temperate 

 and tropical climates. People in temperate 

 climates require more food in winter than in 

 summer. 



Mixed D.iet. From the foregoing statements Planning Meals. With such a knowledge of 



it can readily be seen that while man may foods as is here outlined, the housewife can 



live on an exclusively vegetable diet or an plan meals so as to meet the physiological 



exclusively^ meat diet, he will preserve his . needs of her family, give a good variety of 



