Functions of Food

The term "food" refers to anything, which we take to nourish our body. It includes solids, semi solids and liquids that are consumed by us to maintain our body and keep it healthy. It is ow basic necessity because it contains substances, which perform important functions in our body. These substances are called "nutrients".

It may also contain some non-nutritive substances such as colors and flavor. Hence, food is a complex mixture of different nutrients and non nutrients that can be metabolized by an organism to give energy and build tissue. Food is any substance normally eaten or drunk by living organism and provides mental stimulus for thinking.

Functions of Food

Food is an essential prerequisite for the life and as such the primary goal of eating and drinking is to enable the body to function normally. Food consists in part of various nutrients. There are over forty essential nutrients, which are - supplied by food we eat. These nutrients can be classified into five major categories based on their similar features, proteins, carbohydrates, fats, vitamins

and minerals. Water is important as a nutrient as well as a food.

Each nutrient category has a specific physiological role, refers to role of food in maintaining certain specific body functions. Since food contain nutrients, it has physiological functions too, as social and psychological functions. "We are what we eat" is an old proverb. Our nutritional status, health, physical and. mental facilities depend on the food we eat and how we eat it. Functions of food are

listed in Table.

Functions of Food

Physiological Functions

The physiological functions performed by food are the energy giving, body building, protection and regulation of body processes. Energy is required for performing various types of activities such as sitting, standing, walking, running and performing all our house hold and other works. It is also required for carrying out various activities within the body e.g., beating of heart, contraction of the intestines, expansion and contraction of the lungs. Activities performing within the body also require expenditure of energy. The energy giving function of food is performed by two important nutrients i.e., carbohydrates and fats which are known as body "fuel". When these are burnt, the energy is released in the form of heat which is trapped in high energy compounds of biological system such as ATP. At the time of need, body utilize these compounds to release energy. The process of energy production similar to combustion of coal in air. Food is also needed for growth and repair. Our body is made up of millions of structural and functional units called cells. When growth takes place, new cells are added to the existing ones, which increase in size, get worn out and die and are being replaced by new cells. This process is called as "repair". For both growth and repair, proteins are necessary. Increase in height and weight from infancy to adulthood is possible only by the process of growth.

The other major physiological functions which are performed by food are for protection and regulation of body processes. Protection refers to role of food in preventing infection by ensuring proper functioning of the body systems responsible for fighting infections i.e., if person develop infection or any other type of illness, food and the nutrients it contain, facilitate rapid recovery. A person eating poor diet takes more time to recover.

The regulatory function mentioned earlier refers to the role of food in controlling the body processes. Several processes take place in the body such as the beating of heart, maintenance of body temperature and contraction of muscles. Temperature is maintained at 98.4OF or 37OC. This is achieved by specific nutrients. Similarly, water is also having important regulatory role. Several chemical reactions take place in the body. With the aid of these chemical reactions, simpler substances are used to build more complex ones. Similarly, complex substances are broken down in to their simpler unit. Rate of reaction are controlled according to need of the body. Vitamins, minerals and proteins play major role in controlling these reactions and they act as regulators.

You are being provided with all the components of food in a way similar to medication such as injection or intravenous administration etc. even then, you need food to satisfy yourself. It means our body is having stretch receptor and only the food stuff can satisfy the satiety center. This is another physiological utility of food. Food is the substance behind production. A mother deprived of food can not produce milk. Similarly, a sheep can not produce wool without proper food.

Social Functions

Food and eating has significant social meaning. Sharing food with other person is a symbol of hospitality and friendship throughout the world. We express our hospitality to our guest through an offer of food or a drink. In times of disaster or sorrow, we take food to the affected persons. In our country, offering a cup of coffee or tea is a symbol of friendship.

Food is an integral part of festivity. Joyous occasions such as the birth of child or marriage are celebrated by having feasts and serving delicacies. Festivals like Diwali, Christmas, Eid, Lohri, Dussehra, Pongal, Onam and Holi are celebrated by having special and prescribed menu. So, food serves the function of bringing people together.

Food has also got significance in the religious context. Certain food items such as fruits, sweets and coconuts are offered in the temples. Sweets and "prasad" distributed at the end of religious functions. Different religious communities share common eating pattern. This is because religious texts and practices strongly recommend some foods while rejecting others. So, food has become an integral part of social and religious life of people.

Food is also a good indicator of the state of the environment in which it is produced. Monitoring of environmental contaminants in food, therefore, not only assist in ensuring food safety but can also give early warnings about the state of environment such as level of heavy metal contaminate on to enable appropriate action.

Psychological Functions

Food is a source of security./An infant learns security from the way his mother feeds him. His behavioral patterns will be influenced by the extent to which he feels secured as regards to his food supply. Similarly, a growing child gains confidence and a feeling of belonging when he knows there is food in the house and he will be fed. People feel reasonably secure when they have enough food stored up, to take care of them during periods of scarcity. Familiar foods give a sense of security when one has to eat away from house.

Food is a status symbol. It is prestigious to use polished white rice instead of unpolished rice. The same is true white flour and white bread which have replaced "black bread." The status factor associated with certain foods used by so called upper class makes other prefer them, to easily available less expensive and offer more nutritious foods. We serve certain foods for family and different special foods when we have guests.

Food is an outlet for emotion. As a relief from tension one may eat or not eat. For some people continuous nibbling of food relieves loneliness and boredom. Anger and frustration may turn one against food. Specific foods are associated with unhappy experiences. Food consumed by some people is unacceptable and even revolting for others. Such concepts have no rhyme or they related to nutritive value. They are just emotional reaction. Thus for an average man, food is much more than substances supplying nutrients for health. It is the sum of his culture and traditions, emotional outlet, gratification of pleasure and a relief from stress, a means of communication expressed in food likes and dislikes. The psychological and emotional reactions to food do not yield easily to reasoning or scientific facts about nutrition.