Nutrition: Food & Classes of Food JSS1 Basic Science Lesson Note

FAMILY HEALTH (II): NUTRITION

Nutrition is the process of taking in food to get energy and maintain life. It is also called feeding in living organisms.

FOOD

Food is any substance that, when eaten, is used to maintain life and growth.

Importance of Food

1.                 To give energy
2.                 To maintain life
3.                 It makes us grow
4.                 To make one stay healthy
5.                 It helps to build the body and repair worn-out tissues
6.                 It enables the body to fight against diseases.

FOOD ITEMS OR FOODSTUFFS

These are items or things that we eat. Examples are rice, beans, yam, garri, groundnut, etc.

Meal—This is a combination of two or more food items eaten together.

Diet—This refers to the meals that we eat every day

SOURCES OF FOOD

Food items can be classified into two sources

1.                 Plants
2.                 Animals

Plant sources

1.                   Roots, e.g., cassava, carrot, etc.
2.                 Underground stems, e.g., Irish potato, yam, onion, etc.
3.                   Fruits, e.g., palm oil, tomato, guinea corn, maize, etc.
4.                 Seeds, e.g., beans, groundnut oil, rice, etc.

Animal Sources

These include meat, cheese, chicken, eggs, etc.

CLASSES OF FOOD

Food can be grouped according to the nutrients they contain and the functions they perform:

1. Carbohydrates:

Sources: Rice, Cassava, wheat, maize, millet, potato, etc.

Function: It gives us energy.

2.     Protein

Source: Meat, Fish, beans, groundnut, milk, egg, melon, etc.

Functions:   (i) Repairs of worn-out tissues

                     (ii) It promotes growth

                     (iii) It gives us energy when carbohydrates are lacking in the body.

3.     Fats and oils

Sources: Palm oil, groundnut oil, margarine, butter

Functions:   (i)     Act as an insulator and prevent heat loss

                     (ii)    Provides much energy

                     (iii)   It forms part of the cell membrane

(iv)   It cushions body organs.

4.                 Vitamins

Source: Leafy vegetables, fruits (like oranges, pawpaw, etc.), egg, liver, palm oil.

Functions:   (i)     Promotes healthy body and growth in children.

                     (ii)    Prevent diseases

5.                 Mineral salts:

Sources: Fruit, eggs, milk, dried fish, vegetables

Functions:   (i)     Aids the formation of good bones, teeth, blood, meat and liver

6. Water:

Source: Rain, spring, river, well

Functions:   (i)     component of the blood and flesh

                     (ii)    Aids digestion

7. Roughages:

Source: Vegetables

Functions:  (i) makes food to pass through the digestive system easily.

NUTRIENTS

A nutrient is a chemical or food that provides what living things need to live a healthy life and grow well.  The different classes of food can also be called nutrients.

BALANCED DIET

It is a diet that contains the correct combination of all the classes of food in the required amount or proportions.

Importance of Balanced Diet

1.                 It makes us to stay healthy
2.                 It helps to prevent malnutrition
3.                 It helps to protect the body from diseases.

CLASSWORK

1.                 What is food?
2.                 State four importance of food
3.                 Mention three sources of carbohydrate