7. Nutrition and Diet

Living things take food and water and use them for a variety of purposes such as :
Obtaining energy
Growth of the body
To carry out day to day functions of the body
To fight diseases

Nutrients and foodstuffs

 There are six main nutrients in our food : Carbohydrates, fats, proteins, fibre, vitamins and minerals. These nutrients are present in the different food items we eat in differing proportions. Let us learn more about some of them.

Energy-giving nutrients- Carbohydrates

Our main need is of energy. It is fulfilled by carbohydrates. Hence, our diet includes a large proportion of cereals in the form of rice, chapatti or roti, bhakri and bread which contain carbohydrates. Cereals are our staple food.


Some part of our energy requirement is also fulfilled by fatty foods such as oil, ghee and butter. We get energy in the form of heat from the food we eat. Heat is measured in kilocalories. Hence, the energy in food items is also measured in kilocalories (Calories). Children of growing age need to get approximately 2000 to 2500 Calories from the food they eat.


We need proteins for the purposes of growth, repairing the wear and tear of the body and for other life processes. We get proteins from the sprouts, milk and milk products, meat and eggs in our food.

Minerals and vitamins

 To improve the body’s resistance to disease and for other life processes the body needs vitamins, minerals and fibre in the diet. We obtain these nutrients mainly from vegetables and fruits. We require vitamins and minerals in small quantities, but their deficiency can lead to various diseases. Let us learn more about them. The body needs several inorganic substances. They are called minerals. The table below gives examples of some minerals and provides information about their functions in the body, the various sources of the minerals as well as the diseases caused by their deficiency.


Water soluble vitamins : Vitamin B and Vitamin C dissolve easily in water. So they are called water soluble vitamins. They are thrown out of the body through the water in sweat and urine. Hence, a regular supply of these vitamins is essential. B1 , B2 , B3 , B6 , B9 and B12 are the important types of Vitamin B.

Water insoluble vitamins : These vitamins are insoluble in water but are soluble in fatty substances. They get stored in the body. Vitamins A, D, E and K are fat soluble vitamins.

A balanced diet

All that we consume during the day is together called our ‘diet’. A diet containing adequate quantities of all nutrients is called a Balanced Diet.

 To build a strong and healthy body, you need all nutrients in the right proportion and in sufficient quantities in your daily diet.

Significance of a balanced diet:
l An increased capacity to work.
l Good physical and mental health.
l Increased capacity to fight/resist diseases.
l Helps in proper growth of the body.

How to get a balanced diet?

 To ensure that we get a balanced diet from the food we eat, we can make a food pyramid. All food which we eat is classified into various groups. The space allotted to each food group in the pyramid, depends upon the proportion in which it should be included in our diet. Hence, we can choose foods from each group daily according to the space allotted to it in the pyramid. If we choose some items from each group in the right proportion according to the pyramid shown on page 53, we can make sure that we are getting a balanced diet.


 If we select a daily diet which includes vegetables, fruits, sprouts and cereals according to the pyramid, we will also get fibre in sufficient quantity.

What trouble do we have to face if we do not get enough fibre from our daily diet ? What care must be taken to make sure that fibre is not lost or removed from the food we eat?


Alongwith all the other nutrients, the body also needs an adequate supply of water. For this purpose, we must drink milk, buttermilk, lemon juice, sherbets, fruit juices and plenty of water.


Malnutrition occurs when all the nutrients that the body needs are not obtained in the proper proportions from the diet. This happens when a person does not get sufficient food or when the diet is not balanced. If one’s diet exceeds one’s need, it is called overnutrition.

Junk food

 Chocolates, noodles, burgers, pizzas, chips, bottled soft drinks, attractively packaged snacks as also ready fried foodstuffs available in the market such as wadas, pakodas, etc. are very tasty and we like them very much. However, these foodstuffs contain refined flour, sugar, oil in large proportions. When refined flour, is made from wheat or when sugar is made from sugarcane, many nutrients in the wheat or sugarcane are lost in the process. Hence, all we get from these foods is energy and our hunger is satisfied. Naturally, if we eat a lot of junk foods, we will get insufficient quantities of the items from other food groups. If this happens frequently, our body soon experiences a shortage of proteins, vitamins and minerals and that may lead to malnutrition. Junk food eaten frequently also causes obesity. Obesity is not good for our health. As such foods do not supply all the necessary nutrients, they are called junk foods.

How to avoid obesity?

l Have a balanced diet.
l Eat whole grains. Eat fruits and vegetables with their skins.
l Increase use of bicycles
l Play more outdoor games

l Do not eat if you are not hungry.
l Do not watch TV while eating.
l Do not use motor vehicles for travelling a short distance.
l Avoid precooked, packaged foods.

Adulteration of food

In order to earn more profits, cheaper substances of low quality are mixed with the foodstuffs. These substances are called adulterants and adding them to foodstuffs is called adulteration of food. Adulterants may even be poisonous or harmful to health. Such adulterated food is impure and harmful and so unfit for consumption.


Adulterants used to adulterate food are such that they will remain unnoticed even when mixed with the food.