CHAPTER II. 



NORMAL MILK AND ITS PRODUCTS AS FOOD. 



Food is any substance taken into and used in the body 

 for the purpose of building new tissues and repairing the 

 old, and for supplying the body with heat and energy. 

 The best foods are those which produce the best physio- 

 logical results with the least amount of waste. They 

 must be hygienic, digestible, palatable, furnish the nu- 

 trients needed by the system in proper amounts and be 

 reasonably cheap. 



Milk, properly produced, is a food having all these 

 requirements. 



There are three chief classes of nutrients necessary to 

 maintain the human body: 



1. Fats, sugars, starches and cellulose. These are the 

 chief food elements that produce energy, fat and heat in 

 the body. Cellulose and starch are not found in milk. 

 The sugar and fat are the most important ones. They 

 are found in milk in sufficient and proper quantities to 

 supply the body. 



2. Proteids. These chiefly produce the muscles, tendons 

 and hair. They are also to some extent producers of 

 energy. Good examples of the proteid group are casein 

 and albumen found in milk. 



3. Mineral foods. The chief of these are phosphates, 

 chlorides and other salts, calcium, potash and soda, with 

 small quantities of iron and magnesia. They chiefly pro- 

 duce the bones of the body. 



s 



