Even though the chief function of the food is to supply energy to meet physiological needs and to maintain body in good health, but it serves other functions also. These are described as below:
(a) The body requires nutrients for energy. Energy giving nutrients are carbohydrates, fats and proteins. The human body is never at rest.
Even while sleeping, the heart beats, digestion and respiration continue and the body temperature remains constant. For all these voluntary and involuntary activities, energy is required constantly.
(b) The nutrients build and maintain body tissues. Nutrients necessary for building and maintaining body are proteins, minerals and water. Different parts of human body like muscles, bone and organs are built upon and maintained by the proteins. Minerals like irons, calcium and phosphorus determine and regulate formation of blood and skeletal tissues.
(c) Some nutrients are needed for regulating body processes. Water is required in large amount to regulate body processes, such as digestion, excretion, maintenance of the body temperature and electrolyte balance. Roughage helps normal bowel movements.
(d) Protective foods are required for safeguarding the body against diseases and disorders. Vitamins play a vital role in regulating almost all the body processes like growth, vision, health of skin, formation of proper teeth and good digestion. They also protect the body against diseases. Minerals control some of the physiological processes of the body. For example, deficiency of iodine can lead to a disease of thyroid gland, called goiter.
(e)All the nutrients, except carbohydrates, play an important role in the regulation of body processes, such as circulation of blood, maintenance of body temperature, digestion, etc.
Food is served almost on all social events like marriages, parties, get-together, official meetings etc., in the form of tea, breakfasts, banquet, dinner etc. On all these occasions, food indirectly serves as a powerful and effective instrument for developing social rapport.
Besides other functions, food satisfies certain emotional needs also. Traditional habits are characterized by certain foods, which are pleasing to persons of one culture and same are served invariably to fulfill social and emotional needs of that culture or society.