Protein
Proteins are essential for growth and maintenance of body tissues and for the production of substances such as hormones and enzymes which help to control many functions within the body. If insufficient carbohydrate and fat are available in the diet, then protein may also be used to provide the body with energy.
Proteins are made from building blocks known as amino acids.
There are 20 different amino acids.
Some amino acids can be made in the body and others can only be supplied by the diet -these are known as the essential amino acids.
Some foods are better providers of these amino acids than others. Those which contain all the essential amino acids are known as “high biological value” foods e.g. milk and dairy foods, meat, eggs etc.
Those which contain fewer of the essential amino acids are known as “low biological value” foods e.g. cereals, beans, lentils and nuts.
However if a wide variety of foods are consumed in the correct proportions the different protein sources can work together to provide the ideal levels of the different amino acids.