Let's follow food through your body. Food gives your body energy. Whole grains, beans and starchy vegetables such as potatoes and corn are foods that are high in starch. Saliva starts to break down starches in food while the food is still in your mouth. After you swallow, muscles push food down the esophagus into the stomach. Stomach muscles mix food with digestive juices. Food is broken into tiny pieces so the body can absorb the nutrients it needs. Thirst is the signal that your body is low on water.

Now let's follow food through the intestines. The small intestine takes digested nutrients into the blood. The large intestine absorbs water and turns waste into stool, and water helps move food through the intestines. Fibre is a part of plant foods that helps other food and waste move through the gut. Fibre is a type of carbohydrate that the body cannot digest. Starches are also called complex carbohydrates, and starchy foods are the main source of carbohydrate in our diet.

Now let's look at fat and protein. Fat helps the body absorb vitamins A, D and E. Your body needs protein to repair cells and make new ones. Protein is found throughout the body, in muscle, bone, skin, hair and almost every other tissue. Essential amino acids cannot be made by the body, so they must come from food. Beans are a plant food that gives your body protein. Fish, eggs and meat are foods from animals that give your body protein.

Now let's look at minerals. Minerals are elements from soil and water that plants absorb and animals eat. Calcium helps build strong bones and teeth. Milk, yogurt and cheese are dairy foods that have calcium. Iron helps make red blood cells, which carry oxygen around the body. Beans, nuts and dried fruit are plant foods that contain iron. Zinc helps the body make new cells and heal wounds, and potassium is a mineral found in most foods that helps the heart muscle work and balances fluids in the body.

Last, let's look at vitamins in food. Fruits and vegetables have vitamins, such as vitamin C. Vitamin C helps the body heal wounds, and carrots have substances that your body turns into vitamin A. Vitamin A helps you see in dim light, and the body makes vitamin D when sunlight shines on the skin. Vitamins A, D, E and K are fat-soluble: they dissolve in fat and are stored in the body. Vitamin C and the B vitamins dissolve in water and are not stored, so the body needs a fresh supply each day. Eating a mix of different foods is the best way to get the vitamins and minerals you need.

Words to know

• saliva: mouth juice
• nutrients: food helpers
• potassium: a mineral
• fibre: plant part
• minerals: soil elements
• protein: body builder