1030 SUCCESSFUL FARMING 



stuff is measured by the quantity of heat given off when a given weight of 

 the foodstuff is burned. Such measurements are made by burning a small 

 weighed quantity of the foodstuff in such a way that all the heat produced 

 is used to heat a given weight of water. From the results obtained, the 

 quantity of heat given off, when a pound of the foodstuff is burned, is 

 readily calculated. 



Very careful experiments have been made further to determine the 

 quantity of heat that is yielded to the body when it burns a given weight 

 of a foodstuff. Such experiments have shown that when a pound of 

 protein or of carbohydrate is burned in the body, the body derives 1814 

 calories* of heat, while it derives from the burning of a pound of fat 4082 

 calories of heat. In terms of ounces these figures mean that — 



1 ounce protein yields 113.5 calories of heat to the body. 



1 ounce fat yields 255.1 calories of heat to the body. 



1 ounce carbohydrate yields 113.5 calories of heat to the body. 



Thus, a given weight of fat yields to the body more than double as much 

 heat or energy as the same weight of carbohydrates. Given weights of 

 protein and of carbohydrate yield the body equal amounts of heat or energy. 

 Fuel Value per Pound of Food Material. — In addition to a knowledge 

 of the amount of each foodstuff contained in a given weight of a food 

 material, the woman who would feed her family intelligently should know 

 how much heat these foodstuffs will yield the body. Knowing the number 

 of ounces of each foodstuff contained in a pound of the food material, and 

 also the fuel value per ounce of each foodstuff, she can easily calculate the 

 fuel value of each foodstuff contained in the pound, and readily obtain the 

 total. Thus, a pound of milk (Table I) contains .52 ounce protein, .64 

 ounce fat and .80 ounce carbohydrate; then the fuel-value of each food- 

 stuff is as follows: 



Protein 52 X 113 . 5 = 59 calories 



Fat 64 X 255. 1 = 163 " 



Carbohydrate 80X113.5= 92 " 



Total 314 " 



Hence, the fuel value per pound of milk equals 314 calories. By this 

 method Table II has been prepared. (See following pages.) 



Discussion of Table II. — The first three columns of figures in Table 

 II show the number of calories of heat which the protein, fat and carbo- 

 hydrate contained in a pound of the food material yield respectively when 

 burned in the body. The last column shows the total number of calories 

 of heat the pound yields when burned in the body. 



It should be noted that the pure Ms, i.e., lard and olive oil, yield the 

 greatest number of calories (4082) per pound, while butter is a close second, 



* A calorie is the amount of heat necessary to raise the temperature of 1000 grams (or 2.2 pounds) of 

 water 1° Centigrade or 1°.8 Fahrenheit. 



