Food contains several types of nutrients. They provide energy, the raw materials necessary for growth and repair, and the chemicals needed to make body cells work properly. During digestion these nutrients—proteins, fats, carbohydrates, minerals and vitamins—are absorbed by the small intestine into the bloodstream. Fibre, a nutrient found in plant foods, is not digested, but helps the digestive process work efficiently.

Many vitamins and minerals are needed for good health, but usually in small amounts. Vitamins have letters such as A, B and C. Lack of a vitamin may cause illness. For example, lack of vitamin A from tomatoes, carrots, cheese, fish and liver may result in poor eyesight. Vitamin C, which helps to heal wounds, is found in citrus fruit. Eggs and fish are rich in Vitamin D, which helps your bones grow strong.

​​​​​​​Minerals include calcium and iron. Calcium, for healthy teeth and bones, is found in milk, cheese and vegetables. Iron is found in meat, green vegetables and nuts. It is needed to make red blood cells. Its lack causes a type of anaemia.

Fibre

Dietary fibre is found only in plant foods, chiefly in breads, pastas and other products made from wholemeal grains or cereals, and also in many fresh fruits and vegetables. Cellulose, which makes up the cell walls in plants, is an important fibre.

Fibre is not actually digested and absorbed by the body, but it helps the digestive system to work effectively and stay healthy. It adds bulk to the food so that the stomach and intestines can grip and squeeze the food along.