300 THE ANIMALS AND MAN 



Prof. Atwater of the U. S. Department of Agriculture gives 

 the following table as approximating the average amounts 

 of nutrients needed per day. 



Conditions Proteid 



lbs. 



Man with light muscular work 22 



Man with moderate work 28 



Man with active muscular work 33 



Principles involved in cooking food. — Cooking improves 

 the taste of food, by bringing out its natural flavors. It 

 renders food more wholesome by killing any noxious or poi- 

 sonous organisms that may have collected on it in the mar- 

 kets. It makes the food more digestible by softening the 

 fibers, and in vegetables by bursting the cell walls so that the 

 digestive juices can get at it. 



Economy in the purchase of foods. — The Department 

 of Agriculture at Washington is giving much attention 

 to this subject and bulletins of the results of investigations 

 are published from time to time to furnish information 

 about it. 



"The cheapest food is that which supplies the most 

 nutrient for the least money. The most economical food is 

 that which is cheapest and at the same time best adapted 

 to the wants of the eater. "-J- If we adopt these as rules for 

 the purchase of foods we must study tables of the relative 

 values of foods and consult the markets for relative prices. 



Food accessories. — We commonly add certain things to 

 our foods to make them more palatable, to make them taste 

 better, such as pepper, mustard, vanilla, cinnamon, nutmeg, 

 vinegar, pickles, lemon juice, etc. These are condiments, or 

 flavors, and contain none or but little of the food nutrients. 



*A calory is the accepted unit for measuring heat. It is the amount of 

 heat necessary to raise the temperature of one kilogram of water one degree. 



tFarmers' Bulletin, 23, p. 20. 



