Grade 3 Science (NSO) : Food Part 1 – Food Types

A look at the grade 2 lesson

Grade 2 Science(NSO) : Food

Food can be divided into three types

Energy giving food

Give us energy to work. They contain carbohydrate and fats.


They are found in foods like rice, pasta, cassava, yam etc. when starchy foods are eaten and digested, simple sugars like glucose are obtained. It is this glucose that the body uses for energy.

There are two major types of carbohydrates:

1. Simple carbohydrates (Sugar)

  • Fruits
  • Milk
  • White sugar you would find in a sugar bowl
  • Chocolates

2. Complex carbohydrates (Starch)

  • Bread
  • Crackers
  • Pasta
  • Rice
  • Potatoes
  • Biscuits
  • Noodles
  • Cereal
  • Corn and other grain products

How does the body use energy giving food?

1)    Your body breaks down the carbohydrate into sugars and starches to make a very simple kind of sugar called glucose.

2)    Glucose goes into your bloodstream.

3)    Your blood carries glucose to your brain and your muscles for energy.


Fat in food helps people feel satisfied, so they don’t eat as much. Eating too much fat make you fat and can raise blood cholesterol levels and increase the risk of heart disease.

There are two  types of FAT in foods:

1. Fat from plants (Plant Fat)

  • All kids of oils like olive oil, sunflower oil , coconut oil etc
  • Nuts and peanuts

2. Fat from animals (Animal Fat)

  • Butter
  • Cheese
  • Milk
  • Fish

Why do we need fat?

  •  Fat helps to keep our body warm.
  • Fat gives energy to the body.
  • Fat helps to absorb some vitamins.

Body building food

Many of the foods we eat contain protein. Chicken, eggs, legumes like beans and lentils contain a lot of proteins.

Protiens can be obtained from :


  • Beans
  • Pulses
  • Soya bean
  • Peanuts
  • Cowpea
  • Chickpea


  • Milk
  • Curd
  • Eggs
  • Meat

How does the body use Protein?

The protein found in foods is used by every part of the body to develop, grow and function properly. Protein is a major contributor in human body development. It is essential for antibody production and a healthy immune system

Role of proteins in the body

  • To build up our body parts
  • To maintain our body parts
  • To replace the tissues in our body parts
  • To repair our damaged body parts
  • To keep our body strong
  • Protein improves our ability to learn and concentrate

Protective food

They contain vitamins and minerals and prevent us from falling sick.


There are many types of vitamins as listed below

Vitamins Functions Food 
Vitamin A
  • Gives us a good eye-sight and helps us see at night.
  • Helps to have a healthy skin.
  • Helps us to grow properly.
  • milk fortified with vitamin A
  • liver
  • orange fruits and vegetables (like cantaloupe, carrots, pumpkin, mango, papaw, sweet potatoes)
  • Dark green leafy vegetables (like Spinach, centella)
B VitaminsE.g. – B1, B2, B6, B12
  • Help your body to make protein and energy.
  • Help to make ‘Red blood cells’. Red blood cells carry oxygen throughout the body.
  • whole grains, such as wheat and oats
  • fish and seafood
  • poultry and meats
  • eggs
  • milk and yogurt
  • leafy green vegetables
  • beans and peas
Vitamin C
  • Helps to keep body tissues, such as gums and muscles in good shape.
  • Helps your body heal if you get a cut or wound.
  • Helps your body resist infection. ( makes it a little harder for your body to become infected with an illness)
  • citrus fruits, like oranges and lemon
  • cantaloupe
  • strawberries
  • tomatoes
  • cabbage
  • kiwi fruit
  • sweet red peppers


Vitamin D
  • Needs for strong bones.
  • Forms strong teeth.
  • Helps your body absorb minerals like calcium.
  • milk fortified with vitamin D
  • fish
  • egg yolks
  • liver
  • fortified cereal
Vitamin E
  • Maintains body tissues like in eyes, skin and liver.
  • Protects your lungs from becoming damaged by polluted air.
  • Helps to form red blood cells.
  • whole grains, such as wheat and oats
  • leafy green vegetables
  • sardines
  • egg yolks
  • nuts and seeds
Vitamin K Vitamin K is the clotmaster! What happened the last time you got a cut? Though you were not aware, your blood did something special called clotting.  Clotting takes place when certain cells in your blood act like glue and stick together at the surface of the cut to help stop the  bleeding.
  • leafy green vegetables
  • dairy products, like milk and yogurt
  • soybean oil


Just like vitamins, mineral containing food help your body grow, develop, and stay healthy.

Calcium, Iron, Potassium, Zinc are some of the minerals in our food.

List of food containing minerals

  • bananas
  • tomatoes
  • citrus fruits, like oranges
  • leafy green vegetables
  • dairy products, such as milk, cheese, and yogurt
  • dried fruits, like raisins

How the body uses minerals?

  • They help to build strong and healthy bones and teeth. (E.g. – Calcium)
  • They help to carry oxygen throughout the body by forming ‘hemoglobin’ in red blood cells. (E.g. – Iron)
  • They keep your muscles and nervous system working properly. (E.g. – potassium)
  • They help your immune system, which is your body’s system for fighting off illnesses and infections (E.g. – Zinc)
  • They help with cell growth and helps heal wounds. (E.g. – Zinc)
Another important thing in our daily diet is


Fibre is alo known as roughage. Foods rich in fibre are called fibrous food.  Fibre is found in plants and can not be digested. It helps clean out our intestines by moving bowel movements along.

List of food containing fibre

  • Brown rice
  • Fruit
  • Oatmeal