FOOD MATERIALS 1027 



Both fats and carbohydrates are essentially energy foods; i. e., they 

 do not appear to be repairers of tissue, but they are burned in the body 

 in proportion to the physical exertion that the body puts forth; in the 

 main, they furnish the energy that enables the body to do work, although 

 protein may serve as an energy food. It is very interesting that fats and 

 carbohydrates, which are eaten when not immediately needed as energy 

 foods, seem to be stored as body-fat till sometimes the body becomes 

 much over-weight from the amount of stored fat it is forced to carry about. 

 The carbon of an over-supply of food-protein may also be converted into 

 fat and stored in the body. In a certain sense the fats are more concen- 

 trated foods than the carbohydrates. Fats are about 76 per cent carbon, 

 whereas carbohydrates are 40 to 44 per cent carbon. The fats furnish 

 more than twice as much energy, pound for pound, as the carbohydrates; 

 but apparently the fats are digested, assimilated and used by the body 

 less easily. 



The mineral matters contained in the food are needed, like the 

 proteins, in the repair and growth of tissues — they are needed in 

 every living cell; hence the great necessity of their presence in 

 the diet of both adult and child. They are often called body regula- 

 tors. Fruits and vegetables are very important sources of food mineral 

 matter. 



Proportions of Foodstuffs in Food Materials. — Most food materials 

 contain varying proportions of the different foodstuffs along with water. 

 Consideration of the constituents of some typical food materials will make 

 this clear. 



Average cow's milk consists of 87 per cent water, 3.3 per cent protein, 

 4 per cent fat, 5 per cent carbohydrate and .7 per cent mineral matter; or 

 cow's milk contains 13 per cent of foodstuffs. A quart of standard milk 

 weighs 34.4 ounces. Hence, a quart of whole (unskimmed) milk contains 

 4.46 ounces of foodstuffs; a pint 2.23 ounces and a cup 1.12 ounces. In 

 other words, a quart of milk contains some more than a quarter of a pound 

 of total foodstuffs; while a pint and a cup each contain proportional 

 amounts. 



First patent flour consists of 10.55 per cent water, 11.08 per cent 

 protein, 1.15 per cent fat, 76.85 per cent carbohydrates and .37 per cent 

 mineral matter. Hence a pound (about one quart sifted) of this flour 

 consists of 14^ ounces of foodstuffs, and a pint or a cup contains propor- 

 tional amounts. Note that fine wheat flour is a very concentrated food, 

 since it contains nearly 90 per cent of foodstuffs. 



Whole eggs consist of 11.2 per cent refuse (shell), 65.5 per cent water, 

 11.9 per cent protein, 9.3 per cem fat, no carbohydrate and .9 per cent 

 mineral matter; or whole eggs consist of about 22 per cent foodstuffs. An 

 egg of average size weighs about 2 ounces. Such an egg contains nearly 

 34 ounce protein, a little less than 34 ounce fat and about to ounce 

 mineral matter. It will be discovered that in eggs we have to consider a 



