2. Components of Food

Introduction: In Chapter 1, we made lists of the food items that we eat. We also identified food items eaten in different parts of India. A meal could consist of chapati, dal, and brinjal curry. Another may be rice, sambar and a vegetable preparation of lady’s finger (bhindi).

What Do Different Food Items Contain?

We know that each dish is usually made up of one or more ingredients, which we get from plants or animals. These ingredients contain some components that are needed by our body. These components are called nutrients.

The major nutrients in our food are named:

Carbohydrates
Proteins
Fats
Vitamins
Minerals

In addition, food contains dietary fibres and water which are also needed by our body.

Testing for Nutrients

ACTIVITY 2: Test for Starch

Method: Take a small quantity of a food item or a raw ingredient. Put 2-3 drops of dilute iodine solution on it.
Observation: A blue-black colour indicates that it contains starch.

ACTIVITY 2: Test for Protein

Method: Take a small quantity of food item (paste/powder). Add 10 drops of water. Add 2 drops of solution of copper sulphate and 10 drops of solution of caustic soda.
Observation: A violet colour indicates presence of proteins.

ACTIVITY 2: Test for Fats

Method: Take a small quantity of a food item. Wrap it in a piece of paper and crush it. Straighten the paper and observe.
Observation: An oily patch on paper shows that the food item contains fat.

What Do Various Nutrients Do For Our Body?

Carbohydrates: Mainly provide energy to our body. Sources: Rice, potato, sugar.
Fats: Also provide energy (more than carbohydrates). Sources: Oil, ghee, butter.
Proteins: Needed for the growth and repair of our body. Called "body building foods". Sources: Pulses, milk, meat, eggs.
Vitamins: Help in protecting our body against diseases. Keep eyes, bones, teeth, and gums healthy. (Vit A, C, D, E, K, B-complex).
Minerals: Needed for proper growth and good health. (Iron, Calcium, Iodine).
Dietary Fibres: Also known as Roughage. Mainly provided by plant products (grains, pulses, potatoes, fruits/veggies). Helps body get rid of undigested food.
Water: Helps body absorb nutrients from food and throw out wastes like urine and sweat.

SOLVED IN-TEXT QUESTION: Boojho

Q: Boojho thought that fats would be the best foods to eat, all the time. A katori (bowl) of fat will give much more energy than a katori of carbohydrate rich food, isn't it?

Ans: It is true that fats give more energy, but eating too much fat rich food is harmful as it may lead to a condition called obesity.

Balanced Diet

A diet that contains all the nutrients in right quantities, along with good amount of roughage and water is called a Balanced Diet.

Note: Vitamin C gets easily destroyed by heat during cooking.

Deficiency Diseases

Diseases that occur due to lack of nutrients over a long period are called deficiency diseases.

Vitamin A: Loss of vision (Night blindness).
Vitamin B1: Beriberi (Weak muscles).
Vitamin C: Scurvy (Bleeding gums).
Vitamin D: Rickets (Soft bones).
Calcium: Bone and tooth decay.
Iodine: Goiter (Glands in neck appear swollen).
Iron: Anaemia (Weakness).

Chapter Summary

The major nutrients in our food are carbohydrates, proteins, fats, vitamins and minerals. In addition, food also contains dietary fibres and water.
Carbohydrates and fats provide energy to our body.
Proteins and minerals are needed for the growth and the maintenance of our body.
Vitamins help in protecting our body against diseases.
Balanced diet provides all the nutrients that our body needs, in right quantities, along with adequate amount of roughage and water.
Deficiency of one or more nutrients in our food for a long time may cause certain diseases or disorders.

Exercise Q1

Q: Name the major nutrients in our food.

Ans: The major nutrients in our food are:

Carbohydrates
Proteins
Fats
Vitamins
Minerals

(Plus water and dietary fibres).

Exercise Q2: Name the following

The nutrients which mainly give energy to our body: Carbohydrates and Fats
The nutrients that are needed for the growth and maintenance of our body: Proteins and Minerals
A vitamin required for maintaining good eyesight: Vitamin A
A mineral that is required for keeping our bones healthy: Calcium

Exercise Q3: Name two foods each rich in

Fats: Ghee, Butter
Starch: Rice, Potato
Dietary fibre: Spinach, Cabbage
Protein: Milk, Pulses (Dal)

Exercise Q4: True or False

By eating rice alone, we can fulfill nutritional requirement of our body. (False)
Deficiency diseases can be prevented by eating a balanced diet. (True)
Balanced diet for the body should contain a variety of food items. (True)
Meat alone is sufficient to provide all nutrients to the body. (False)

Exercise Q5: Fill in the blanks

Rickets is caused by deficiency of Vitamin D.
Deficiency of Vitamin B1 causes a disease known as beri-beri.
Deficiency of Vitamin C causes a disease known as Scurvy.
Night blindness is caused due to deficiency of Vitamin A in our food.

Key Facts and Definitions

1. Nutrients

The components of food that are necessary for growth and maintenance of our body. The major nutrients are Carbohydrates, Proteins, Fats, Vitamins, and Minerals.

2. Deficiency Diseases

Diseases that occur due to lack of specific nutrients in the diet over a long period are called deficiency diseases.

3. Vitamin Deficiency Chart

Vitamin/Mineral	Deficiency Disease	Symptoms
Vitamin A	Loss of Vision (Night Blindness)	Poor vision, loss of vision in darkness.
Vitamin B1	Beriberi	Weak muscles and very little energy to work.
Vitamin C	Scurvy	Bleeding gums, wounds take longer to heal.
Vitamin D	Rickets	Bones become soft and bent.
Calcium	Bone and tooth decay	Weak bones, tooth decay.
Iodine	Goiter	Glands in neck appear swollen.
Iron	Anaemia	Weakness.

4. Important Types

Energy giving foods: Foods containing Carbohydrates and Fats.
Body building foods: Foods containing Proteins.
Protective foods: Foods containing Vitamins and Minerals.

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