Components of Food

"The food we eat consists of carbohydrates, fats, proteins, vitamins, water, minerals & fibres".

1.0Introduction

We know the importance of food, it is required for growth, maintenance of the body and also to protect us from diseases. We eat a large variety of food and people from different parts of our country have different food habits. Some people prefer rice, others take chapatis or meat and fish.

Nutrients are the substances in the food that every living organism need to make energy, grow, develop and reproduce. There are seven essential components or substances called nutrients in our food. They are - (i) Carbohydrates (ii) Fats (iii) Proteins (iv) Mineral salts (v) Vitamins (vi) Water (vii) Fibre (also called roughage)

There are two main types of nutrients. (i) Macronutrient: It consists of carbohydrates, fats and proteins which are required in large amount in the diet. (ii) Micronutrient: It consists of vitamins and minerals which are required in small amount in the diet.

Carbohydrate

Carbohydrates are as important to body as fuel is to car. These are the common energy-giving compounds. There are two major types of carbohydrates in food: sugar and starch. Sugar is used to provide energy immediately. Starch releases energy more slowly than sugar.

Foods rich in carbohydrates are potato, sweet potato, bread,

Some sources of carbohydrates

rice, wheat, honey, common sugar, jaggery (gur) and milk. Most food items usually have more than one nutrient. However, in a given raw material, one particular nutrient may be present in much larger quantity than in others. For example, rice has more carbohydrates than other nutrients. Thus, we say that rice is a "carbohydrate rich" source of food.

Fats

Fats too provide us energy, producing more energy than carbohydrates.

Fat- rich foods are - (i) Milk products such as butter and cheese (ii) Vegetable oils such as coconut oil, groundnut oil (iii) Nuts (iv) Milk (v) Animal fat from meat.

Fats provide more than double the energy provided by carbohydrates but still carbohydrates are the preferred source of energy because fats make energy available at a slower pace.

(a) Plant sources

(b) Animal sources

Functions of Fat

(i) Efficient source of energy. (ii) Forms an insulating layer beneath the skin to prevent excessive heat loss. e.g., blubber in polar bear. (iii) Formation of fat-soluble vitamins and various hormones.

Building Concepts

On what factors the nutritional requirement of the body depends?

Explanation

The nutritional requirement of the body depends upon the age, sex and kind of work a person does like a growing child needs more carbohydrates & proteins than an ageing person. Similarly, a man needs more nutrients than a woman, person who do physical labour needs more energy giving foods.

2.0Proteins

These are body-building foods. Proteins help the body in its growth, repair of body cells and tissues. Protein sources of plant origin include pulses, soyabeans, peas and to a lesser extent cereals. Meat, eggs, cheese, milk and fish provide proteins of animal origin.

(a) Plant sources

(b) Animal sources

Some sources of proteins

3.0Mineral Salts

Mineral salts are important for various body functions. They are required in small quantities and are obtained from the food we take in. Minerals have no energy value. Rich sources are milk, cheese, green leafy vegetables (like spinach), pulses, meat and eggs.

Sources of mineral

Three main groups of food -

4.0Vitamins

Vitamins are neither body building nor energy giving food but are very important for proper functioning of our bodies. Some vitamins can be produced by our body, but most have to be supplied through food. Vitamins are classified into two types Fat soluble vitamins - A, D, E, K.

Water soluble vitamins - B and C

Some sources of Vitamin A :

Sources of Vitamins:

Building Concepts

What is the importance of vitamins in our diet?

Explanation

Vitamins help in protecting our body against diseases. They also help in keeping our eyes, bones, gums, skin and teeth healthy. Water Water is indispensable. About 70 percent of our body weight is that of water. It helps the body in various functions. It is a means of transporting substances in the organism. It helps to maintain a constant body temperature. Water helps in the absorption of food and excretion of waste products from the body in form of urine and sweat. Our body needs 2-3 litres of water every day.

Some vitamins are very sensitive to heat and light. For example, vitamin C is easily destroyed during cooking. Therefore, vitamin $C$ rich food should be eaten raw.

Building Concepts

How can we get adequate amount of water in our diet?

Explanation

Most of the water can be obtained by drinking liquids such as water, tea, milk, juices. In addition to this, water is also added to food while cooking. Some fresh vegetables and fruits also contain some amount of water.

5.0Dietary fibres / Roughage

Roughage is the fibrous indigestible material in food that promotes the elimination of wastes from large intestine. Fibres mainly come from plants. Fibre is the substance that gives plants their form. The fibres that we eat are known as dietary fibres. Whole grains and pulses, potatoes, fresh fruits and vegetables are main sources of roughage.

Sources of roughage

6.0Balanced Diet

A diet that contains adequate amount of different components of food required for the healthy functioning of our body is called a balanced diet. According to scientists, a balanced diet must include foodstuffs from the following four basic food groups: (i) Milk group: Includes milk and milk products. (ii) Meat group: Includes meat (chicken, fish, lamb, etc.) and meat substitutes (beans, peas, nuts, and seeds). (iii) Fruit and vegetable group: Includes fruits and vegetables. (iv) Grain group: Includes breads and cereals.

Effects of Cooking on Nutrients

7.0Chapter at a Glance

8.0Some Basic Terms

• Origin : The point from which something starts.
• Indispensable: Very important.
• Indigestible : Food that cannot be digested (breakdown) easily.
• Elimination : Get rid of something.
• Essential : Completely necessary.
• Peeling : To take the skin off a fruit or vegetable.
• Stunted : To stop somebody/something from growing or developing properly.
• Discolour : To make something change colour.
• Suffering : To experience something unpleasant (not nice).
• Recommended : To say that something is good.
• Immediately : Without delay (late)
• Dilute : To make a liquid weaker by adding water.
• Deficiency: The state of not having enough of something.
• Disability : The state of being unable to use a part of your body properly.
• Adequate: Sufficient.