84 



OUR FOOD SUPPLY 



the only food nutrients that contain the element nitro- 

 gen. 



We must be careful not to eat too much protein, 

 however. We should eat just enough protein food 

 (lean meat, eggs, fish, etc.) for tissue building and 

 eat plenty of carbohydrates and fats to furnish the 

 necessary energy for the body. This is wise for at 

 least two reasons. First, carbohydrates and fats, as 

 a general rule, are less expensive than protein foods. 

 Second, protein foods are more difficult to digest and 

 they produce waste materials which put a strain on 

 the liver and the kidneys. 



A mixed diet is best, that is, we should select our 

 foods to include all the nutrients, minerals, vitamins, 

 and water. When our diet contains the proper 

 amounts and proportions of these essentials we say 

 it is balanced. It is not possible for us to state here 

 what this balance is for every individual. That de- 

 pends on height, age, weight, sex, occupation, and 

 climate. Each person must determine for himself what 

 is the proper balance of foods for him. Your weight 

 is one good index of whether your diet is balanced. 

 If you are considerably above normal weight for your 

 age, height, and sex you should eat less of carbo- 

 hydrates and fats. If you are considerably under nor- 

 mal weight you may not be getting enough of the 

 right kinds of foods or something may be wrong with 

 your body. It is always well to consult a doctor about 

 these matters. 



The following simple rules may be used as general 

 guides to healthy eating. 



Eat at least twice as much of carbohydrates as of 

 proteins and fats combined. 



Eat a mixed diet containing varieties of plant and 

 animal foods to satisfy the normal appetite. 



Include liberal amounts of milk, butter, and fresh 

 green vegetables and fruits in your diet. 



Eat some food every day that will supply "rough- 

 age" in the diet, such as whole wheat bread, bran 

 muffins or cereals, fruits, and coarse vegetables. 



Eat sparingly of concentrated foods such as candies 

 and cakes, especially before mealtime. 



Drink plenty of water. Many doctors recommend 

 at least six glasses a day. When you drink with your 

 meals do not use the water to dissolve or wash down 

 the food. 



Why is milk sometimes called the perfect food? 

 Milk is one of our best and most widely used foods. 

 Figure 125 shows the substances which are present in 

 milk. When milk is "taken apart" it is found to con- 

 tain the following : carbohydrates in the form of sugar, 

 fats, and proteins in forms easily digested by most 

 persons, and the minerals calcium and phosphorus, 

 both of which are necessary for the building of sound 

 teeth and bones. In addition to these substances milk 

 is rich in vitamins A and B. 



Milk is not quite a perfect food because it is de- 

 ficient in certain minerals, especially iron. It is 



