Protein is essential for growth and repair work. It provides the body with energy and is needed for the manufacture of hormones, antibodies, enzymes, and tissues.

Amino acids

Before protein can be utilised for these functions, the body breaks it down into amino acids, the building blocks of all proteins. Some of these amino acids are known essential - they must be obtained from the diet because the body is unable to synthesise them from other amino acids. The non-essential amino acids can be made by the body if the diet is otherwise adequate.

Complete and incomplete

Dietary proteins are divided into two groups: complete and incomplete (complementary). Complete proteins contain ample amounts of all eight essential amino acids and are found in meat, fish, poultry, cheese, eggs, and milk. All soya bean products such as tofu, TVP (textured vegetable protein), soya flour, and soya cheese are also complete proteins.

Incomplete proteins contain only some of the essential amino acids and therefore need to be combined with other foods - usually complex carbohydrates - which contain the missing ones. For example, beans or lentils and brown rice or whole-wheat will form a high-quality complete protein. In fact, a combination of any whole grains, any nuts and seeds, any pulses (legumes), peanuts and a variety of vegetables will make a 'first-class' protein.

03/06/2009