Why do we need food?

Think about everything you did today: waking up, walking to school, reading, playing and even sleeping. Every one of these needs energy, and that energy comes from the food we eat. Food also helps us grow taller and stronger, heals a scraped knee, and protects us from falling ill. The useful substances in food that do all this work are called nutrients, and the way our body takes in and uses them is called nutrition.

The main nutrients

Our food contains five main kinds of nutrients, plus two other things the body cannot do without. Each one has its own special job.

Carbohydrates and fats are called energy-giving foods, proteins are body-building foods, and vitamins and minerals are protective foods. Nutrients needed in large amounts, such as carbohydrates, proteins and fats, are sometimes called macronutrients, while vitamins and minerals, needed in tiny amounts, are called micronutrients.

The five food groups

An easy way to plan meals is to think of five food groups: grains (rice, roti, poha), fruits, vegetables, protein foods (dal, eggs, fish, nuts) and dairy (milk, curd, paneer). Picture your plate divided into parts. About half should be fruits and vegetables, about a quarter should be grains, and about a quarter should be protein foods, with a glass of milk or a bowl of curd on the side. Fats, oils and sweets are used only in small amounts.

What is a balanced diet?

A balanced diet gives the body all the nutrients, roughage and water it needs, in the right amounts. A plate of only rice gives energy but not enough protein or vitamins. A plate of only fruit gives vitamins but not enough energy. Mixing foods from all the groups keeps us healthy, active and growing well.

When nutrients are missing

If the body does not get a nutrient for a long time, a deficiency disease can develop. Too little vitamin C can cause bleeding gums, too little vitamin D can make bones weak, too little iron can make us tired and pale, and too little iodine can cause a swelling in the neck. A balanced diet prevents these problems.

Where does our food come from?

Most of our food comes from plants: grains, pulses, fruits, vegetables, nuts, oil seeds and spices. Some comes from animals, such as milk, eggs, fish, meat and honey. Farmers grow and raise this food, and it travels from fields and farms to markets, kitchens and finally our plates.

Smart eating habits

• Never skip breakfast. After a long night, the body needs fuel to think and play at school.
• Drink plenty of water, about 6 to 8 glasses a day and more in summer.
• Limit junk food such as chips, fried snacks and fizzy drinks, which have lots of fat, salt or sugar.
• Wash vegetables before cutting and cook them with a lid on to save vitamins.
• Eat slowly and chew well so that digestion can start in the mouth.

This Food and Nutrition worksheet for Class 4 brings these ideas to life on WitKnowLearn with an online quiz, online activities and interactive games. Flip the cards, balance plates in the Plate Lab, play the games, do the science labs, take the challenges and then carry out real food tests in the Virtual Lab.