Protein

Protein and Its Importance

What are Proteins?

  • Proteins are large, complex molecules that are essential for the structure, function, and regulation of the body.
  • They’re made up of smaller units called amino acids, which are linked together in long chains.
  • There are 20 different types of amino acids that can combine to make a protein.
  • Our bodies can produce 11 of these amino acids, but the remaining 9 — known as the essential amino acids — must come from the food we eat.

Role of Proteins in the Body

  • Proteins are crucial for the growth and repair of cells — particularly during childhood and adolescence, but also throughout life for tissue repair and replacement.
  • They’re required for the structure of all cells and tissues, including muscles, bones, skin, hair, and nails.
  • Proteins play a vital role in many body functions, including hormone and enzyme production, immunity, and carrying oxygen in the blood (haemoglobin is a protein).

Protein in the Diet

  • Good sources of protein include meat, fish, eggs, dairy products, beans, nuts, and seeds.
  • Animal sources provide all the essential amino acids so are known as complete or high-quality proteins.
  • Plant sources of protein often lack one or more essential amino acids, but a varied diet of different plants can meet protein needs.
  • The reference nutrient intake (RNI) for adults in the UK is 50g of protein per day.

Protein Deficiency

  • Protein deficiency can lead to growth problems, a weakened immune system, and muscle wastage.
  • Severe protein deficiency can cause a condition called kwashiorkor, characterised by swollen stomachs in children, often seen in countries where famine or a poor diet is prevalent.

Protein Excess

  • Consuming too much protein can place extra strain on the kidneys and liver as they have to break down the excess.
  • As many high-protein foods are also high in saturated fats, too much protein could lead to high cholesterol levels or other health problems.
  • However, for most people in the UK, the risk of getting too little protein is of more concern than the risk of getting too much.