Functions Of Food, Food Groups, Food Pyramid

The civilised man does not eat all the food as it is available in the nature. He cuts, cooks, processes and modifies the food in many ways before consuming.

Food: It is defined as anything solid or liquid which can be swallowed, digested and assimilated and nourishes in the body.

Functions Of Food

Energy Yielding:

This group includes foods rich in carbohydrates, fats and protein. One gram of carbohydrate gives 4 calories. One gram protein gives 4 calories, One gram of fat gives 9 calories.

1g CHO = 4

1g protien =4

1g fat =9

By using this we can estimate the no.of calories from our diet.

This group is divided into 2 groups

1.Cereals, Pulses, Nuts And Oil Seeds, Roots And Tuber

2.Pure Carbohydrates Like Sugar And Fats And Oils

Cereals provide in addition to energy large amounts of protein, minerals and vitamins in the diet. Pulses also give protein and vit-B besides giving energy. Nuts and oil seeds rich in energy yielding as they are good source of fats and proteins.

Roots and tubers though mainly provide energy, they also contribute to some extent to minerals and vitamins. Pure carbohydrates like sugars provide only energy and fats provide concentrated source of energy and fat soluble vitamins.


Foods rich in protein are called body-building foods. They are also classified into two groups.

  1. 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.

2. Pulses, Oil Seeds And Nuts: They are rich in proteins but may not contain all the essential amino acids required by human body.

Protection And Regulation:

Foods rich in protein, vitamins and minerals have regulatory functions in the body.

Eg: Maintaining the heartbeat, water balance, temperature. Protective food are broadly classified into two groups:

1.Foods rich in vitamins and minerals and proteins of high biological value eg: milk, egg, fish,liver.

2. Foods rich in certain vitamins and minerals only eg: green leafy vegetables and fruits.

Maintenance Of Health:

Foods contain certain phytochemicals and antioxidants which helps in preventing degenerating diseases. Foods plays an important role in prevention of cancer, heart diseases and in controlling diabetes mellitus. Some examples for functional foods are whole grains, soya bean, green leafy vegetables, coloured fruits and spices.

Food Groups

Foods have been classified into different groups depending upon nutritive value, for the convenience of diet plan.Food groups like Basic four, suggested by ICMR can be used for planning diets.

Basic Four Food Groups Suggested By ICMR:

1.Cereals And Millets: Rice, wheat, ragi, maize, bajra, jowar, rice flakes, puffed rice.
Pulses And Legumes: Bengal gram ,black gram, cow pea, peas, rajma, soya beans.

Energy, protein, invisible fat, thiamine, riboflavin, iron, folic acid and fibre.
2.Milk And Animal Products:
Milk, curd, skimmed milk, cheese.
Chicken, liver, fish, egg and meat.
Protein, fat, riboflavin, calcium
protein, fat and iron.
3.Vegetables And Fruits:
Green leafy vegetables:
amaranth, gogu, spinach, drumstick leaves, coriander leaves, fenugreek.
Other vegetables:carrots, onions, brinjal, ladies finger,beans, capsicum, cauliflower, drumstick.
Fruits: Mango, guava, tomato, papaya, orange, sweet lime, watermelon.

Riboflavin, folic acid, calcium, fibre
carotenoids and fibre

carotenoids, vit-C, riboflavin, folic acid, iron, fibre.
4.Oils, Fats And Nuts:
Oils and fats:butter, ghee, hydrogenated fat, cooking oils.
Sugar and jaggery
Energy, essential fatty acids and fat soluble vitamins.
Energy, jaggery has iron.
protein and omega-fatty acids.

Food Pyramid

Food pyramid is designed to know about healthy foods and in which proportions they should be consumed. Healthy foods consists carbohydrates, proteins, fats, vitamins and minerals in correct proportion.

Same nutritive value foods are kept together in each block of the pyramid. Food Pyramid as a guide will help you get the right balance of nutritious foods within your calorie range. Studies show that we take in too many calories from foods and drinks high in fat, sugar and salt, on the top shelf of the Food Pyramid, but they are less in vitamins and minerals.