In selecting our foods we should think of two things: first, the value of the food as a heat-producer or as a building material; and second, the cost of the food. We may like butter much better than bacon, but we should remember that, pound for pound, bacon has a greater nourishing power than butter, and a pound of bacon will cost far less than a pound of butter.[1]
Vegetable foods produce heat by means of the starch which they contain. All vegetables contain starch. This starch is changed into a kind of sugar in the body, and when thus changed it is used to produce heat and power. All vegetable foods do not have the same heat-producing power. There is more heat-producing power in a pound of oatmeal than there is in ten pounds of cabbage. Ten cents' worth of dried beans will produce more heat in the body than will a dollar's worth of lettuce. Thirty cents' worth of corn meal will do more building in the body than will a piece of mutton worth a dollar and a half; but you would have to eat a large amount of corn meal in order to secure the building effect that would result from eating a small quantity of mutton. In most fruits the only nourishing quality is in the sugar they contain. This sugar produces heat in the body just as starch does.
The real value of advertised foods
You will see some foods advertised as possessing a wonderful nourishing power. Do not let such statements deceive you, for no food can have a greater nourishing power than the things from which it is made. If the particular food advertised is made from wheat flour, its nourishing power is just the same as that of an equal quantity of wheat flour. If it is made from corn meal, it can have no greater nourishing power than has the meal itself.
We have learned something about the materials necessary in food and why they are needed. We must now learn why foods that contain these materials sometimes do not give us as good results as we might hope for.
Questions. 1. What use does the body make of new cells? 2. How does the body keep itself warm? 3. Name two uses that the body makes of food. 4. What foods are especially useful for making cells? 5. What foods are chiefly used for making heat? 6. Select articles of food for two meals of equal nourishing value, one meal to be expensive and the other inexpensive. 7. How would you determine the real value of any food?
Remember. 1. Foods are used to make heat and power in the body and to make the body grow. 2. The foods that make the body grow are called building materials, and lean meat is the best kind of building material. 3. The foods that produce heat and power in the body are called heat-producing materials, and fats and starches are the best heat-producers. 4. All vegetables contain starch, some of them contain a fatty oil, and most of them contain some building material. 5. You can get as much building and heat-producing material from cheap foods as you can from expensive foods.