What does protein do in the body?

Protein has a lot more roles in the body than you might think, and these are not just linked to building and maintaining muscle. As an essential macronutrient, getting the right amount of protein is important to provide us with energy and support a number of functions within the body1

But what does protein do exactly, and what does the body use protein for? Let’s take a look. 

Exploring the key role of protein in the body

There are many different types of protein in the body. When we consume proteins through our diet, the body converts them into amino acids (aka the building blocks of protein) which it then uses for different processes in the body to keep us healthy and functioning at our best1,2

Each protein within the body has a vital part to play, supporting2,3,5:

  • The growth and repair of body tissues

  • The activity and production of enzymes

  • The immune response 

  • Transporting nutrients.

The benefits however don’t end there. Proteins also form key structures within the body such as our muscles, bones, and skin2,3.  For example, collagen is a structural protein found abundantly in our skin. 

Ultimately, protein is very important, supporting our health from the inside out!

protein meal

Protein and enzymes

Enzymes are proteins which support several critical processes within the body such as breathing, moving and the digestion of food 4,5

Tiny chemical reactions are happening in our bodies all the time - like cogs turning to keep our bodies running smoothly. Enzymes increase the rate of these chemical reactions. To give you an idea of just how important enzymes are, without them, most chemical reactions wouldn’t be quick enough to keep us alive!5

Protein and the immune response

The immune system is a complex collection of cells and functions that work together to protect your body from illness and infection7

Your body works hard around the clock to create lots of different proteins, including immunoglobulins (more commonly known as antibodies)8. These antibodies play a key role in protecting you when you encounter a virus or harmful bacteria. Your immune system is very clever, storing all of this information so that it can recognise which antibodies are needed the next time you come into contact with a similar bacteria or virus7.

Protein in nutrition and diet

So, how can you make sure you’re including enough protein in your diet? 

Whilst the amount of protein the body needs will vary for each person, it’s recommended that the average healthy adult here in the UK has an intake of 0.75 grams of protein per kg body weight per day (9). Athletes or regular exercisers will likely have higher protein requirements depending on the intensity and type of exercise they do10. You can learn more about how much protein the body needs here.

Luckily there are plenty of food sources of protein that are easy to incorporate into your diet. Some good examples include2

  • Lean meat and poultry

  • Fish and shellfish 

  • Eggs 

  • Dairy products such as milk, yoghurts, and some cheeses

  • Soya plant-based alternatives to dairy (such as soya drinks and yoghurts)

  • Pulses and legumes (chickpeas are a good example)

  • Nuts and seeds

Read more

  1. World Health Organization. Macronutrients [online] 2023. Available at https://www.emro.who.int/health-topics/macronutrients/introduction.html#:~:text=There%20are%20three%20broad
  2. British Nutrition Foundation. Protein [online]. Available at https://www.nutrition.org.uk/healthy-sustainable-diets/protein/. [Accessed November 2023]
  3. Solano F. Metabolism and Functions of Amino Acids in the Skin. Adv Exp Med Biol. 2020;1265:187-199. doi: 10.1007/978-3-030-45328-2_11. PMID: 32761577
  4. Ianiro G, Pecere S, Giorgio V, Gasbarrini A, Cammarota G. Digestive Enzyme Supplementation in Gastrointestinal Diseases. Curr Drug Metab. 2016;17(2):187-93. doi: 10.2174/138920021702160114150137. PMID: 26806042; PMCID: PMC4923703
  5. Lewis T, Stone WL. Biochemistry, Proteins Enzymes. [Updated 2023 Apr 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554481/
  6. Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. Chapter 6, How Cells Read the Genome: From DNA to Protein. Available from: https://www.ncbi.nlm.nih.gov/books/NBK21050/
  7. Marshall JS, Warrington R, Watson W, Kim HL. An introduction to immunology and immunopathology. Allergy Asthma Clin Immunol. 2018 Sep 12;14(Suppl 2):49. doi: 10.1186/s13223-018-0278-1. PMID: 30263032; PMCID: PMC6156898
  8. Justiz Vaillant AA, Jamal Z, Patel P, et al. Immunoglobulin. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513460/
  9. COMA. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom – Report of the Committee on Medical Aspects of Food Policy. Published 1991. London: TSO
  10. Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. Published 2017 Jun 20. doi:10.1186/s12970-017-0177-8