Food provides our body with the materials it needs to grow, work, and stay healthy. But not all food items are the same. Some give us energy quickly, some help us grow, and some protect us from diseases. The chemicals present in food that our body can use are called nutrients, and the substances that make up our food are called the components of food. In this chapter, we learn about these components, their functions, and the foods that provide them.
The major components of food are carbohydrates, fats, proteins, vitamins, minerals, water, and roughage. Each of these has a specific job to do in the body. Carbohydrates and fats provide energy, proteins help in growth and repair, while vitamins and minerals keep our body working properly. Water helps in many body processes, and roughage helps in digestion.
This chapter also introduces the idea of a balanced diet. A balanced diet contains all the nutrients in the right amounts. The chapter also covers the concept of deficiency diseases, which occur when our body does not get a particular nutrient for a long time. By the end of this chapter, we understand why we must eat a variety of foods and why no single food can give us everything.
The food we eat contains a mixture of several components. These are grouped into two broad categories: nutrients and non-nutrients.
Nutrients are the components that the body needs and can use. The main nutrients are: - Carbohydrates - Fats - Proteins - Vitamins - Minerals
Non-nutrients are components that do not provide nourishment but are still important: - Water - Roughage (dietary fibre)
Every nutrient has a specific role. Carbohydrates and fats are energy-giving foods. Proteins are body-building foods. Vitamins and minerals are protective foods because they keep us healthy and protect us from diseases. Water and roughage help in the smooth functioning of the body and in digestion.
It is important to understand that no single food item contains all the nutrients in the right amounts. This is why we need to eat a variety of foods from different groups to get everything our body needs.
Carbohydrates are the main source of energy for our body. They are made of carbon, hydrogen, and oxygen. When we eat carbohydrate-rich food, our body breaks it down to release energy that we use for all our activities, from running and jumping to thinking and breathing.
Carbohydrates are found in many common foods. The main sources are: - Cereals: wheat, rice, maize, bajra, jowar - Sugars: sugar, jaggery, honey - Fruits: banana, mango - Vegetables: potato, sweet potato - Millets and grains
There are different types of carbohydrates. Starch and sugars are the most common. Starch is found in grains and potatoes, while sugars are found in sweet foods. When we chew a piece of bread or rice for some time, it tastes slightly sweet. This is because the starch in it gets broken down into sugar by the saliva in our mouth. This is a simple test we can do at home.
Carbohydrates are our quick source of energy. Athletes, labourers, and growing children need plenty of carbohydrates because they use up a lot of energy. If we eat more carbohydrates than we need, the extra energy is stored as fat in the body.
Fats also give us energy, but they provide more than twice the energy that carbohydrates provide. Fats are called concentrated sources of energy. They are stored in the body and used when the body needs extra energy. Fats also keep our body warm and protect our internal organs.
The main sources of fats are: - Vegetable oils: groundnut oil, mustard oil, soybean oil, sunflower oil - Animal fats: butter, ghee - Nuts and oilseeds: groundnut, mustard seeds, sesame seeds - Some fruits: avocado
Although fats are important, we should not eat too much of them. Eating too much fatty food can make us overweight and can lead to health problems. On the other hand, eating too little fat is also harmful. The body needs a balanced amount of fat for good health.
Proteins are called body-building foods because they help in the growth and repair of the body. Our muscles, skin, hair, nails, and even our blood are made partly of proteins. When we are young, proteins help us grow taller and stronger. When our body gets hurt, proteins help repair the damaged tissues.
Proteins are made of smaller units called amino acids. The main sources of proteins are: - Plant sources: pulses (dal), gram, beans, peas, soybeans, groundnuts - Animal sources: milk, eggs, fish, meat, paneer
People who eat only plant food can still get enough protein from pulses, legumes, and soy products. Growing children, pregnant women, and people who are recovering from illness need extra proteins.
Vitamins do not give us energy, and our body needs them only in very small amounts. Yet they are extremely important for good health. Vitamins protect our body from diseases and help various body functions run smoothly. Our body cannot make most vitamins on its own, so we must get them from food.
The main vitamins and their functions are: - Vitamin A: Keeps our eyes and skin healthy. Sources: carrot, papaya, mango, milk, egg, leafy vegetables. - Vitamin B complex: Helps release energy from food and keeps nerves healthy. Sources: whole grains, green vegetables, meat, milk. - Vitamin C: Prevents scurvy, keeps gums and teeth healthy, and helps heal wounds. Sources: citrus fruits like orange and lemon, amla, green vegetables, tomatoes. - Vitamin D: Helps our body use calcium for strong bones and teeth. Our body makes Vitamin D when the skin is exposed to sunlight. Sources: sunlight, egg yolk, fish, milk. - Vitamin K: Helps in blood clotting. Sources: green leafy vegetables.
Deficiency of vitamins causes deficiency diseases. For example, lack of Vitamin A causes poor vision (night blindness), lack of Vitamin C causes scurvy, lack of Vitamin D causes rickets (weak bones), and lack of Vitamin B can cause beri-beri.
Minerals are needed by our body in small amounts but are essential for many functions. They help build strong bones and teeth, form blood, and keep our body working normally. Important minerals include calcium, phosphorus, iron, and iodine.
Just like vitamins, deficiency of minerals also causes diseases. Anaemia is a common mineral deficiency disease caused by lack of iron, and goitre is caused by lack of iodine.
Water is an essential component of food, even though it does not provide energy. Water helps in digestion, absorption, and transportation of nutrients in the body. It also helps in removing waste products and regulates our body temperature. Our body loses water through sweat and urine, so we must drink enough water every day.
Roughage, also called dietary fibre, is the part of food that our body cannot digest. Roughage is found in the husks of grains, in fruits, vegetables, and salads. Even though it is not digested, roughage is very important because it helps in removing undigested food from the body and prevents constipation. Foods rich in roughage include whole grains, fresh fruits, vegetables, and salad.
Neither water nor roughage provides nutrients, but both are essential for good health. A healthy diet must include plenty of water and roughage.
A balanced diet is one that contains all the nutrients, in the right amounts and the right proportions, along with water and roughage. It provides enough energy and materials for growth and repair, and protects the body from diseases.
A balanced diet for a growing child should include: - Cereals and grains (energy) - Pulses, milk, eggs, or meat (proteins) - Vegetables and fruits (vitamins, minerals, and roughage) - Oil, ghee, or butter (fats) - Plenty of water
The quantity of food needed varies from person to person. It depends on age, sex, and the amount of physical activity. A labourer doing heavy physical work needs more energy-giving food than a person who sits at a desk all day. A growing child needs more proteins and minerals than an elderly person. Therefore, a balanced diet is not the same for everyone.
When our body does not get a particular nutrient for a long time, it becomes deficient in that nutrient. This leads to deficiency diseases. Each deficiency disease is caused by the lack of a specific nutrient.
Deficiency diseases can be prevented by eating a balanced diet. Foods rich in the lacking nutrient should be included in daily meals.
We can test for the presence of some nutrients in food using simple methods: - Test for starch: Add a few drops of iodine solution to the food sample. If the colour turns blue-black, starch is present. - Test for fats: Rub the food sample on a piece of paper. If an oily translucent spot appears, fat is present. - Test for proteins: Add a few drops of copper sulphate solution and caustic soda solution to a food sample in a test tube. If the colour turns violet, protein is present.
These simple tests help us understand which nutrients are present in which foods. For example, a potato turns blue-black with iodine, showing it has starch, and a piece of butter leaves an oily spot on paper, showing it has fat.
| Nutrient | Function | Main Sources |
|---|---|---|
| Carbohydrates | Provide energy | Wheat, rice, sugar, potato |
| Fats | Provide concentrated energy | Oil, ghee, butter, nuts |
| Proteins | Growth and repair of body | Pulses, milk, egg, meat |
| Vitamins | Protect from diseases | Fruits, vegetables, milk |
| Minerals | Build bones, form blood | Milk, green vegetables, salt |
| Water | Digestion, transport, temperature | Water, juicy fruits |
| Roughage | Helps in digestion | Fruits, vegetables, whole grains |
| Deficiency Disease | Nutrient Lacking | Symptoms |
|---|---|---|
| Night blindness | Vitamin A | Poor vision in dim light |
| Scurvy | Vitamin C | Bleeding gums |
| Rickets | Vitamin D | Weak, bent bones |
| Anaemia | Iron | Weakness, tiredness, pale skin |
| Goitre | Iodine | Swelling in the neck |
| Beri-beri | Vitamin B1 | Weakness, nerve problems |
In this chapter, we discovered that our food is made of several components, each with a special role. Carbohydrates and fats give us energy, proteins build and repair the body, vitamins and minerals protect us from diseases, and water and roughage keep the body functioning smoothly. We learned that no single food is complete, which is why a balanced diet containing all nutrients in the right amounts is essential. We also studied how the deficiency of specific nutrients leads to diseases like night blindness, scurvy, rickets, anaemia, and goitre, and how these can be prevented through proper nutrition. By understanding the components of food, we can make wiser food choices and lead healthier, happier lives.