Food and Nutrition

From earliest times man has realized that providing food for himself and his family is one of his and his family is one of his major tasks. He soon recognized that food sustains life and that a full stomach brings happiness and contentment. Tor a long time, however, he did not understand the relationship of food to health. It has been largely in the present Century, through the tireless work of men and women engaged in scientific research, that man has come to appreciate the body’s delicate and efficient mechanism and has learned something about the physiological processes by which the body makes food into bone, blood, brain, and brawn.

The human body in its functioning is far more amazing than the finest watch or the most intricate machine. There is, however, a striking similarity between the body and a machine. Human bodies need fuel just as machines require fuel or other sources of power. Every breath taken, every beat of the heart, every movement of the body requires energy. Food supplies fuel to yield this energy. The remarkable difference between the human body and a machine is the way in which the body can repair its own worn parts. When a machine needs a new art or needs an old part mended, it must remain idle until the damaged part is repaired or replaced by a mechanic. In contrast, the human body is able to repair itself to a large degree.

The substances of which foods are composed are called nutrients. Each of them is needed by the body and each has its own special function to perform. The most familiar of the nutrients are proteins, fats, carbohydrates, vitamins, and the many mineral elements, such as calcium, iodine, and iron. These are the materials by which the body meets its needs for building and repairing tissues, providing heat and energy, and regulating its physiological functions. Whether well or ill, the body must have these substances. The choice of food should therefore be regulated first of all by the body’s needs. This does not mean that preference, custom, convenience, availability, and cost must be set aside and the diet limited to a few foods. On the contrary, if the food needs of the body as well as the composition of the different commonly used foods are understood, it is easy to plan meals that are both adequate and varied.

No single food can be depended upon to furnish enough of all the nutrients required for health. The problem in planning meals the nutrients required for health. The problem in planning meals for each day is therefore to choose those foods that together will supply all the nutrients needed to build, maintain, and repair the body structure, to regulate the many body processes, and to provide sufficient energy for the activities of the body.

Sometimes illness occurs because of a serious lack of one or more of the specific nutrient substances that the body must have to function properly. More often the person who for sometime has had an inadequate diet does not become critically ill or even sick enough to go to bed. He may simply feel run down, tired, and unable to work. On the other had, the person who is selecting his food wisely and is enjoying what he eats has a good chance of feeling and keeping well.