Report of Missouri Farmers' Week. 181 



The usual way of recording the food value of any given dietary 

 is in terms of the calorie, a calorie being the amount of heat re- 

 quired to raise the temperature of one kilogram (a little over a 

 quart) of water one degree centigrade. The amount of heat given 

 off by the various food principles has been determined by the 

 calorimeter, an instrument, as its name implies, used for determin- 

 ing the heat-producing value of various materials. One gram 

 (about 1-29 of an ounce) of sugar or starch yields 4.1 calories; one 

 gram of fat, 9.3 calories, twice as much as that given off by the 

 same amount of sugar, while one gram of protein yields heat equal 

 in amount to that of the carbohydrates (sugar and starch) , namely, 

 4.1 calories. 



The amount of heat given off by the body at rest and during 

 certain forms of mechanical work has likewise been determined 

 in terms of calories. Thus by knowing these two factors, the amount 

 of heat given off by the body and the amount of heat produced by 

 the various foods, we can determine, vdthin very narrow limits, 

 the amount of food which the body needs. By scientific investiga- 

 tion it has been found that a child of two requires food which 

 yields about 1,313 calories per day; a child of eight, about 1,525 

 calories, and a child of fourteen, approximately 2,500 calories per 

 day. As we have already said, the fuel supplied to the body must 

 be given in the form of fat, carbohydrates and protein; the water 

 and mineral matter, although necessary, yield no heat. The amount 

 of fat and carbohydrates may vary within fairly wide limits, for 

 these fulfill no specific function other than supplying energy to the 

 body; but the amount of protein supplied must be rather definite, 

 for this is used to build and repair muscle and nerve tissue, a 

 function which cannot be taken over by either of the other two food 

 materials. It is always better to err on the side of giving too much 

 protein than too little, for if too much is supplied the body can 

 eliminate the unused portion, whereas if too little is given, the body 

 cannot develop normally. Forty grams of protein seems an aver- 

 age amount for the child of two, fifty grams for the child of eight 

 and sixty for the child of fourteen. The menus recorded above 

 have been worked out with these figures as a basis. Thus it will 

 be seen that in menu I, for the two-year-old, the protein, 30 grams, 

 yields 120.72 calories. This leaves 1,193 calories to be supplied 

 by the fats and carbohydrates. In this menu the carbohydrates from 

 the milk, bread, jelly, cookies, oatmeal, sugar, crackers, potatoes, 

 apples and peas furnished 634.16 calories, and the fats from the 

 butter, cream, milk, cookies, etc., furnished 558.7 calories. By 



