We all need food to work and play. Food provides us energy to work. We also need food for our body to grow, and to remain healthy by fighting disease.
Food keeps our bodily part strong. Eating only one type of food will not give everything to our body because food-stuffs contains some substances for doing different things useful for the healthy growth of the body, giving energy that needs to work, play and protecting it to fight from diseases. These substances are called nutrients. Some nutrients provide us with energy, some help us to grow and some help us to fight disease. Different foods have different nutrients. Therefore to remain fit and healthy we need to eat different foods.
These nutrients are proteins, carbohydrates (sugar and starch), fats, vitamins and mineral salts.