Life cannot be sustained without adequate nourishment. Man needs adequate food for growth and development and to lead an active and healthy life. Nutrition is the science of foods, the nutrients and other substances therein, their action, interaction and balance in relationship to health and disease. Health is defined by The World Health Organisation as the state of complete physical, mental and social well being and not merely the absence of diseases. Therefore Food plays an important role in maintaining a person's nutritional and health status.
Man must eat to live and what he eats will affect to a high degree his ability to keep well, to work and to live long. Food performs many vital functions in the body.
This group includes foods rich in carbohydrate, fat and protein. They may be broadly divided into two groups.
Cereals, pulses, roots and tubers: Cereals provide in addition to energy large amounts of proteins, minerals and vitamins in the diet. Pulses also give protein and B vitamins besides giving energy to the body.
Fats, Oils and pure carbohydrates like sugars: Sugars provide only energy and fats provide concentrated source of energy.
Foods rich in protein are called body building foods. They are classified into two groups.
Milk, egg, meat & fish. They are rich in proteins of high biological value. These proteins have all the essential amino acids in correct proportion for the synthesis of body tissues.
Pulses, nuts and oilseeds: They are rich in protein but may not contain all the essential amino acids required by the human body.
Foods rich in protein, vitamins and minerals have regulatory functions in the body like maintaining the heartbeat, water balance, temperature, etc.
Protective foods are broadly classified into two groups.
Foods rich in vitamins and minerals and proteins of high biological value (eg) milk, egg, and fish.
Foods rich in certain vitamins and minerals only (eg) green leafy vegetables and fruits.