Nutrition is the science that deals with all the various factors of which food is composed and the way in which proper nourishment is brought about.

To live one must eat. But, we not only eat to live, what we eat also affects our ability to keep healthy, do work, to be happy and to live well. Knowledge of what to eat and in what quantities is a prerequisite to the healthy and happy life. The average nutritional requirements of groups of people are fixed and depend on such measurable characteristics such as age, sex, height, weight, and degree of activity and rate of growth.

Food is anything solid or liquid that has a chemical composition, which enables it, when swallowed to do one or more of the following

1. Provide the body with the material from which it can produce heat, or any for m of energy.
2. Provide material to allow growth, maintenance, repair or reproduction to proceed.
3. Supply substances, which normally regulate the production of energy or the process of growth, repair or reproduction.

Good nutrition requires a satisfactory diet, which is capable of supporting the individual consuming it, in a state of good health by providing the desired nutrients in required amounts. It must provide the right amount of fuel to execute normal physical activity. If the total amount of nutrients provided in the diet is insufficient, a state of under nutrition will develop.

The council on Food and Nutrition of the American Medical Association defines nutrition as “The science of foods, the nutrients and the substances therein, their action, interaction and balance in relation to health and diseases. Nutrition science is the area of knowledge regarding the role of food in the maintenance of good health. Thus nutrition is the study of food at work in our body.

Health is defined by the World Health Organization of the United Nations as the “ State of complete physical, mental and social well- being and not merely the absence of disease and infirmity (or ill- health/illness)”

Nutrition is one key to developing and maintaining a state of health that is optimal for you. In addition, a poor diet coupled with a sedentary lifestyle are known to be risk factors for life- threatening chronic diseases and death: Heart disease, Stroke, Hypertension, Diabetes and some forms of Cancer. Together these diseases account for two- thirds of all deaths in the United States. The major health problems in the United States are largely caused by excessive energy intake and not enough physical activity.