942 NUTRITION AND HEAT REGULATION. 



p Heat Valub 



Protein. Fat. ^^^^2^^' Ash. in Calories 



DRATE. Pj,j^ Pound. 



Beefsteak, porterhouse 19.1 17.9 .... 0.8 1110 



Beefsteak, round (lean) 20.2 2.4 .... 1.2 475 



Corned beef (canned) 26.3 18.7 .... 4.0 1280 



Veal, leg (lean) 19.4 3.7 .... 1.1 520 



Veal liver 19.0 5.3 .... 1.3 575 



Mutton, leg (lean) 16.5 10.3 .... 0.9 740 



Pork, ham (fresh, lean) 24.8 14.2 .... 1.3 1060 



Pork chops, medium fat 13.4 24.2 .... 0.8 1270 



Chicken (fowl) 13.7 12.3 .... 0.7 775 



Shad 9.4 4.8 .... 0.7 380 



Shad roe 20.9 3.8 2.6 1.5 600 



Eggs 11.7 10.7 .... 0.7 680' 



Milk 3.3 4.0 5.0 0.7 325 



Oatmeai 16.1 7.2 67.5 1.9 1860 



Rice 8.0 0.3 79.0 0.4 1630 



Wheat fiour (entire wheat) 13.8 1.9 71.9 1.0 1675 



Green peas 7.0 0.5 16.9 1.0 465 



Potatoes (raw) 2.2 0.1 18.4 1.0 385 



Spinach 2.1 0.3 3.2 2.1 IIQ 



Tomatoes 0.9 0.4 3.9 0.5 105 



Apples 0.4 0.5 14.2 0.3 290 



Bananas 1.3 0.6 22.0 0.8 460 



vitamins, in spite of the fact that they contain but httle energy 

 that can be utihzed by the body. Moreover, recent work, ah-eady 

 referred to (p. 901), makes it increasingly probable that the dif- 

 ferent proteins or even the different carbohydrates or fats may be 

 found to have each a specific influence upon metabolism. In these 

 respects the subject of dietetics has a wide field for investigation. In 

 a general way, however, the heat enerpy of a food expresses its value 

 as a means for supplying the energy needs of the living cells. In the 

 work that these cells perform, whether it is contraction, secretion, 

 or nervous activity, energy is needed, and this energy is carried 

 into the body in the potential chemical energy of the proteins, fats, 

 and carbohydrates, whatever may be the source from which these 

 foodstuffs are obtained. 



Dietetics. — -The subject of the proper nourishment of individ- 

 uals or collection of individuals in health and in sickness is treated 

 usually in works upon hygiene or dietetics. The practical details 

 of the preparation and composition of diets must be obtained 

 from such sources.* The general principles upon which practical 

 dieting depends have been obtained, however, from experimental 

 work upon the nutrition of man and the lower animals, some 

 account of which has been given in the foregoing pages. In a: 



* For practical directions, see Gautier, "L'alimentation et les regimes," 

 1904; Blyth, "Foods: their Composition and Analysis " ; Rose, "Feeding the. 



FamUy," New York, 1916. 



