Cost of Food j 359 



The human machine 



The human body is a living machine whose purpose it is to transform 

 one kind of energy into another kind. The main part of the food that 

 goes into the body machine each day should be of a sort that will yield 

 energy. One of our needs is to find food which will supply that energy 

 at the least cost and in a form which will give the best service. It is the 

 same old problem that we have had before us in dealing with the cost of 

 running the cookstove, furnace, or steam engine; but now the problem 

 has its human application. 



Best fuels for the body. — The substances which are cheapest and which 

 give best service to the body as fuels — that is, as energy yielders — 

 are the sugars, starches, and fats. Therefore, foods such as cereals or 

 cereal products, legumes, potatoes, butter, fat meats, oils, must occupy 

 a prominent place in the family dietary. 



Body-building substances. — The human machine, like other machines, 

 requires various materials for repairing it and building it up. The main 

 building material of the living tissue of the body is the substance known 

 as protein. Lean meat, white of egg, casein of milk, gluten of wheat, are 

 all typical protein substances. Other materials are also required for 

 body building and body welfare, and must not be neglected when the cost 

 of food and its uses in the body are being considered. Bones, muscles, 

 and nerves all need lime and phosphorus, red blood must be supplied with 

 iron. Sodium, chlorin, magnesium, potassium, and a number of other 

 substances of less defined use, are all necessary not only to the welfare 

 of the body but to its ability to continue its existence. Their cost must 

 also be reckoned in the purchase of food. 



How foods may be compared as to real cost 

 If, then, the cost of food is to be judged, the specific food needs of the 

 body must first be determined, then the various foods must be compared 

 as to their ability to satisfy each of those needs. 



The trained housekeeper will soon begin to ask herself which foods are 

 cheapest as a source of energy, and which as a source of protein, iron, 

 lime, or some one of the other substances needed by the body. The cost 

 per pound will finally take its right place in her mind as something 

 with which to reckon, but not as something by which to be overwhelmed. 

 She will find that a food which is a decidedly expensive source of energy 

 may on analysis prove an indispensable source of iron or of lime; that a 

 food which is an expensive source of protein may be exceedingly cheap as 

 a source of energy; or that a food which seems expensive as a source of 

 both protein and energy is still a cheap food because of its supply of iron 

 or lime or phosphorus. And so she will test each food and make her final 

 choice on an intelligent basis. 



