Protein is needed to build, repair and maintain body tissues, organs and cells in all parts of the body. Proteins are complex molecules and are made up of different combinations of smaller units called amino acids. Our body can make some of the amino acids needed to manufacture protein and other necessary substances, but certain amino acids must come from the food we eat each day. These are known as the essential amino acids and are required throughout our life.
If a food provides all the essential amino acids for human needs, it is called a high quality or complete protein food.
Beef and lamb are high quality, complete protein foods with an optimum balance of essential amino acids. A 150g serving of lean beef or lamb provides about 21g protein meeting at least a third of the daily protein requirement for adults.
Plant proteins do not contain all the essential amino acids for human needs, so are considered low quality protein when eaten in isolation. Plant proteins can be combined to give the full complement of essential amino acids, eg baked beans on toast.
Click here for a table which compares the nutrient content of major protein foods within the New Zealand diet.