Food and health

Why do we take food ? It is interesting to notice what the lower animals are eating ; for some kinds of food we share with them, and what food does for them it does for us. There are the calves, who live at first upon milk, like the baby at home. We can see how much they have all grown through the summer* The awkward, long-legged fowl running about with such energy are very different from the balls of yellow down that came from the shell in the spring. They have lived upon grain chiefly, but see what they have gained in weight ! One astonishing thing about the young wild birds is their rapid growth ; and, although angleworms would seem a disagreeable diet to you, the young robins like them as much as you do mutton chops or roast beef. Food for growth. One fact, then, about food is this : it gives us material for our bodies, for making bones, muscle, fat, blood, hair, and teeth. But more important still is the fact that some fbods build our bodies better than others. The picture (Fig. 2) shows that there is a difference in the feeding of animals ; for these pigs are the same age, and belong to one family, but they have eaten different kinds of food. When the Pleasant Valley pupils looked at this picture, John Stark was eager to tell the story of a prize pig raised by his cousin in the next [illustration: Courtesy of the United States Department of Agriculture.] Fig. 2. — Litter mates. Frank Ross, who belongs to a pig club, had a contest with his uncle. From the same litter they selected two pigs as nearly alike as possible. Frank followed the directions given by the U. S. Department of Agriculture, and his uncle treated the other pig as he had always done. This is what happened : Weight Cost of Food Selling Price Frank's pig 520 lb. ^15.54 $58.00 Uncle's pig 65 lb. 5.00 8.06 Think over what we have just said about the calf and the chicken, and you can name two kinds of food that are good body builders. There are no wild creatures near Pleasant Valley that live upon flesh, except the hawks among the birds ; but where foxes are still found they thrive upon meat food, and, of course, the young lioh of hot countries grows upon a flesh diet. Food for life and work. Food plays another part that we INTRODUCTORY 7 can understand when we recall what happens to people who starve in times of famine or war. The body becomes weak, unfit for work, and all movements finally stop. Sit perfectly still for a moment. Are all parts of your body quiet .? No ! Your eyelids are winking, you are breathing, your heart is beating; and there are other movements which you cannot feel, such as the constant flow of the blood. Touch your own hand, — how warm it is ! Your clothing makes you warm only by keeping in the heat of your body. What, then, is the source of this heat .? You can give the answer yourself, can you not .? It is your food that gives you body warmth and power to work. All the foods already mentioned give this energy. What facts about the baby and calf and young robin prove this ? The sugar and the fat in the milk are two substances that furnish the energy, and for this reason they are called fuel foods. Another substance found in milk and meat is both a body builder and a fuel food. This substance you will study in Lesson 4. Water and mineral matter. Water is another important part of our food and drink. Still there is something else, that we cannot see, which serves as food for the body. When wood is, thoroughly burned, you know that it leaves ash. Food materials do the same thing when they are burned as completely.^ This white or gray ash does not burn because it is made up of mineral substances, lime, iron, and many others. These are most important for our bodies. Both water and the mineral substances help in body-building. We shall learn more about them later on.