Proteins are composed, like carbohydrates, of carbon, oxygen, and hydrogen, but with nitrogen. They may also contain sulphur and phosphorus. They are complex molecules composed of amino acids.
Proteins are used by the body to:
• enable growth, development and repair.
• build structures such as muscles, tissues and organs, including the heart, lungs, digestive organs.
• enzymes, such as those required for digestion.
• hormones, such as those for the endocrine glands.
Proteins, therefore, are needed not only for obvious body structures, such as muscles, but also for the immune and digestive systems, etc.
Complete proteins are obtained from meat, fish and dairy products including eggs. Proteins can also be obtained from certain combinations of foods, for example, cereals and beans.