Food makes your body work, grow and repair itself. The kind of food you eat can affect the efficiency of these processes. Body function and the food that sustains it is infinitely complex. Food is in fact one of the most complicated sets of chemicals imaginable.
Getting to know which nutrients are in which foods can help you to understand something of this complex relationship between your food and your body.
FOOD is required for two purposes – to build up the body and repair tissue waste, and to supply potential energy, which can be converted into heat and work.
The body uses food to perform one or more of four main functions: to supply energy, for growth and repair, for regulation and for protection.
FUNCTIONS OF FOOD
The functions of food can be broadly classified into three main categories.
1) Physiological functions of food.
2) Psychological functions of food.
3) Social function of food.
1) Physiological functions of food
The physiological functions of food can be further sub-divided as follow:
c.Regulatory and protecting functions of food.
a)Energy giving: The body needs a constant supply of energy to carryout the involuntary processes of which we are not even aware, like, respiration, circulation of blood etc. which are essential for continuance of life. Energy is also required to carry out voluntary activities like professional, household and recreational activities, which every human being indulges in like, either jumping, walking, playing etc. Besides this some amount of energy is also required to convert the ingested food into usable nutrients in the body and the heat released during this process helps to keep the body warm. Energy is mainly provided to our body through carbohydrates and fats in the food. Rich sources of carbohydrates are cereals, sugar, jiggery, potatoes, honey etc. Good Sources of fats include ghee, oil, nuts etc. A major part of our daily diet is constituted by these energy-rich food materials.
b)Body Building: The foods we eat become a part of us. Thus one of the most important functions of food is that of building the body. A newborn body weighting 2.7-3.2 Kg. Can grow to its potential adult size of 55-70 Kg., if right kinds and amounts are eaten from birth to adulthood, In adult life, the food eaten each day helps to maintain the structure of the adult body, and to replace worn out cells of the body.
Building of new tissues is very important particularly for the growing children and pregnant women. There is also a continuous breakdown of old tissues and building up of new tissues going on in our body at all ages irrespective of the apparent growth, thus maintaining a need for body building nutrients.
For the body building purposes, the major nutrients utilized are proteins and minerals. Proteins are mainly provided through milk and milk products, meat, fish, poultry, nuts, soybean, and pulses etc.
c)Regulatory and Protective function: The third physiological function of food is to regulate the activities of the body. It includes regulation of such varied activities as beating of the heart, maintenance of body temperature, muscle contraction, control of water balance, clotting of blood, removal of waste products from the body etc. For any of these processes, one or the other nutrients is responsible. For example Vitamins of the B groups are an integral part of the enzymes and are responsible for metabolizing food and thus release energy. Vitamin K is an essential factor in clotting of blood.
Apart from regulating our body processes, food also protects us from various infections, diseases, and injuries. For example, Consumption of Vitamin A and Vitamin C rich food help in building resistance in the body to fight against invading organism.
The main nutrients which perform these functions include proteins, vitamins, minerals, water and roughage. Although these nutrients are required by the body in very small amounts, yet it is very important for them to be present in our daily diets. The major sources of these protective and regulatory nutrients are green leafy vegetable, milk, fresh fruits and vegetable, fish etc.
2) The Psychological Functions of food
The second major function of food is the psychological function. Food must also satisfy certain emotional needs. These include sense of security, love and attention. Everyone grows in a particular culture with its own unique food habits of that culture and caste.
The person begins to associate the food habits and foods commonly consumed by him, as it gives him a sense of security and satiety. The foods daily eaten by us, give us more mental satisfaction, even a nutritional balanced meal may not be satisfying to the individual, if food include is unfamiliar or distasteful to him/her.
In a friendly gathering, one may try unfamiliar foods and thus enlarge our food experiences. During the course of time and repeated experience, strange foods become familiar and new tastes are formed. These new taste are developed should again be satisfying to the mind. For example, a person accustomed to traditional Indian cusine, takes time to adjust to Chinese or western dishes, but feels mentally satisfied at the site of familiar foods.
3)Social function of Food
Food and eating has significant social meaning. Share food with any other person implies social acceptance. When you share a meal with anyone else, you are expressing your acceptance of friendship and respect for that person. Earlier only persons enjoying equal status in society eat together. A person would never share a meal with someone inferior to him in social terms. Food is also a symbol of our social life. Food is a medium through which we express our happiness. For example, feasts are given at specific states of life, such as birth, mundane ceremony, birthday, marriage etc. Sweets are also distributed and exchanged to mark certain auspicious occasion like festivals. Food is the common link in a meeting, party or get-together that attracts people to come to such social gatherings. Refreshment served even at officials meeting creates a relaxed atmosphere, where people can exchange their views. The menu for such get-to-gather should bring the people together, rather than divide them. Foods help to strengthen mutual friendship.
For example, inviting friends and relatives over meals signify acquaintance and hospitality. Food also has a specific significance and meaning in the religious context. Certain food items such as fruits, sweets, and coconut are offered to the deity in temples. Often sweets are prepared at temples and gurudwaras and distributed to devote as a benediction or prasad.
Further, people of a given religious community share a common eating pattern. This is because religious texts and practices strongly recommend some foods while rejecting others. Food thus becomes an integral part of the social and religious life of people.
Thus it can be concluded that food performs various important functions from satisfying hunger to building mutual understanding and above all helps to maintain our health and adequate nutritional status.
classification of Food
Foods are complex substances composed of chemical constituents called nutrients. According to the presence of such nutrient, foods has been classified as proteins, carbohydrate, fats, vitamins, minerals, water and roughage.
2. Dietary Sources:
Food can also be obtained from animal as well as plant kingdom; that is organic as well as inorganic sources. Organic sources are meat, fish, egg, milk and milk products. Inorganic sources are cereals, pulses, vegetables etc.
Food can also be classified according to the function it performs:
- Body-building foods- Protein, Minerals
- Energy giving foods- Carbohydrates, Fats
- Protective foods- Vitamins, Minerals.
- Regulatory foods- Water, Roughage.
Proteins, carbohydrates and fats are called “Proximate Principles”. They are oxidised (i.e. burnt) in the body to provide energy to the body to carryout all activities of life. In addition to water, which is also a necessary dietary element, proximate principles form the main bulk of the diet. Vitamins and mineral salts do not supply energy, but they play an important role in the regulation of several essential metabolic processes in the body.