We eat food whenever we feel hungry. Wherever some function(s) of body starts slowing down, the need to replenish one or more nutrients is felt in the form of hunger.

Food actually a complex organic substance (nutritive substance) which is consumed by living beings for growth, work, and repair of worn out (depleted) parts and maintenance of life process.

Food has many components, each providing one or another nutrient. In fact nutrients (food item) can be broadly classified either according to their composition or according to their functions.

Main components of food are given below:


(a) Cereals, roots and tubers.

(b) Protein giving foods

(c) Fats and oils, sugar and jaggery.

(d) Protective vegetables and fruits.


(e) Other vegetables.

Here it must be carefully noted that one single component can not fulfill all the requirements of body.

Hence components from each group needs to be included in daily diet for a balanced diet. Several items belonging to each group are available and for variety of taste, appeal, pleasure; one has wide range of choice.

Cereals, Roots and Tubers


The item of this group primarily supplies energy or calories. Examples in this group are rice, wheat, jowar, bajra, ragi and other cereals, tapioca, potato, sweet potato colocasia etc.

This group provides significant amount of calories, proteins, iron and vitamins. These foods are cheap and are consumed in large amount.

Protein Giving Foods

The item in this group is important sources of protein, though cereals also provide protein. Pulses(Dals), grains, peas, beans, groundnuts, cashew nuts, coconut, milk, curd, paneer, khoya, eggs, fish, mutton and other flesh foods make up this group. It includes protein both from the vegetable and animal kingdom.


Milk and dairy products are important sources of calcium and riboflavin. They are second only to the meat group for their protein contribution. Meat, fish and eggs are very rich for protein, iron and niacin, vitamin B6 and B12.

Eats and Oils, Sugar and Jaggery

All these foodstuffs, i.e., vegetable oils, ghee, butter, cream, sugar, jaggery etc. supply energy or calories. This group contributes for about 1/6th of the energy content of the diet, but does not add to the protein, mineral or vitamin levels. Although oils should be used sparingly in the diet, they add variety of taste and flavour to the food.

Protective Foods- Vegetables and Fruits


This group mainly consists of minerals and vitamins, and classified into three groups:

Class A: Green leafy vegetables – spinach, methi, colocasia leaves etc.

Class B: Yellow orange fruits and vegetables- mango, carrots, yellow pumpkin, papaya etc.

Class C: Fruits and vegetables rich in vitamins C -amla, guava, lemon, orange, phalse, etc.


Fruits and vegetables are mainly the suppliers of minerals and vitamins. They are important source of ascorbic acid (vitamin C) and also contribute half of the Vitamin A requirement along with 1/5th of the iron required, making them just second to the meat and flour and cereal groups in importance.

Other Vegetables

These provide variety in taste and texture and provide roughage in the diet, e.g., fruits, stems, leaves and flowers of plants, ladies fingers, brinjals, bitter gourds, cabbage, cauliflower, drumsticks and cucumber. All these vegetables supply vitamins and minerals in enough quantities.

We have studied about various items of different food groups and now we shall make an attempt to understand various relevant details of each food group.

These food items are classified either according to their nutritional values or according to functional values as given below: