All you need to know about this power nutrient
What do you think of when you think of protein? Muscles and a big chunk of red meat? Well, you wouldn’t be wrong, but there is so much more to protein!
What is protein and what does it do?
Protein is one of the three macronutrients (often called ‘macros’) and is made of amino acids, usually referred to as the building blocks of life. When consumed through food and drink, the body breaks the protein down back into amino acids and distributes throughout the body.
Protein has many different roles within the body. It supports muscle contraction and movement, helps hormones to coordinate various functions within the body, and it even forms antibodies to support our immune system. It can be used as an energy source but only when carbs and fats are not available. In fact, protein’s primary function is the build-up of all tissues: from muscles to nails, neurons to bones, skin to hormones. Protein even helps to create our tears! Every single tissue is built up using protein.
More recently, protein has become quite the fashion staple. From the rise in influencers recommending the keto diet to fitness gurus selling protein powders and potions, it has become challenging to discern what we really need to know.
Read on for the latest science!
How much protein do you need?
When it comes to the optimal amount of protein, the answer can vary as it depends on many different factors such as gender, age, activity levels, and health status. For the general adult population in the United Kingdom (U.K.), the current reference nutrient intake (RNI) is 0.75g per kilogram (kg) of bodyweight per day [1]. So, if you’re a female that weighs 65kg, you should be aiming for roughly 49g of protein on a daily basis.
However, this recommendation (originally formed in 1991!), is on the lower side of what research now suggests is the preferred amount. For an active person, an intake between 1.2g – 2.0g per kg of bodyweight per day is optimal [2] and this can increase to around 3.3g for body builders [3].
Who should take particular care with their protein intake?
Elderly people
As we get older, we are more susceptible to a condition called sarcopenia; a loss of muscle-mass and strength. In addition to this, our anabolic response to dietary protein (the building of muscle) lowers as we age, so we need to increase our usual intake to match our protein requirements. It might be useful to spread evenly your protein intake across the day, as it may improve how protein is being utilised by the body.
Athletes and Body builders
Both athletes and body builders typically need a higher protein intake compared to the general population due to the increase in demand from using muscle and energy during training. Amongst the various roles of protein mentioned above, increased protein will also contribute to muscle recovery and enhancing performance, both very important for athletes and body builders alike.
People with type 2 diabetes
Protein can be particularly helpful for blood glucose management, a key focus for people with type 2 diabetes. When the pancreas struggles to produce enough insulin – a hormone essential in the regulation of blood sugar – protein, more specifically some amino acids, can help by stimulating insulin secretion, supporting more stable blood glucose levels. Protein may even improve the pancreas function long-term, when part of a carefully planned and balanced diet [4]
Women during menopause
During menopause, musculoskeletal health becomes particularly important as women are at increased risk of sarcopenia (loss of muscle mass) and osteopenia (loss of bone density). Protein, alongside other nutrients like calcium and vitamin D, and regular resistance training, plays a crucial role in mitigating these risks. [5] Plus, during menopause women may become a bit more insulin resistant. Another good reason to include protein in the diet.
When should you consume protein?
It is generally considered best to spread out your protein intake throughout the day and include at least one source with every meal. This should help you to feel satiated for longer, reducing mindless snacking throughout the day. For those that exercise, it is preferable to consume 0.25-0.3g/kg within two hours of exercise to stimulate muscle protein synthesis, but don’t forget to include your carbohydrates too to replenish your glucose stores.
Evidence is always evolving!
Whilst the general consensus has been to spread your protein consumption across the whole day, a recent study [6] found that one large intake of 100g of protein may also work just as well, if not better. More research is needed here to draw a definitive conclusion so it’s best to focus on what we can be sure of – protein is essential for good, overall health, so it’s best to consume it whenever you can manage. As little as 5g of protein can stimulate muscle protein synthesis so every little helps! [7].
Sources of protein and quality
Foods that contain protein are often split into two different categories; animal-based or plant-based. While choice and personal preference play a role, quality is an important factor to consider, especially when it comes to plant proteins.
High-quality protein sources provide a balanced profile of essential amino acids – the building blocks the body can’t produce on its own – as well as a high concentration of protein per serving. Animal-based proteins like chicken, fish, eggs, and dairy naturally offer a complete range of essential amino acids and are densely packed with protein, making them efficient sources.
For those on a plant-based diets, it’s helpful to focus on foods that come close to this balance. Ingredients like tofu and tempeh provide a solid amount of protein and a good amino acid profile. Quinoa and hemp also contain all essential amino acids, though a lower protein density, while some legumes such as lentils and chickpeas are high in protein but don’t have all the essential amino acids. Other plants like nuts, seeds and grains contribute different amino acids in varying quantities. This makes it really important to prioritise consuming a variety of sources throughout the day to ensure you’re covering all essential amino acids.
An extra nugget of information:
If you’d like to learn a bit more about the amazing benefits of eating beans, read this blog post!
The infographic below can be used to understand different protein sources and the amount of protein in a general portion size. As you can see protein can be found in a lot of various food, even in bread! Could you be tempted by a different protein-rich source ? If so, add it to your shopping list this week and increase your protein variety!
Food highlight!
Mycoprotein is a high-protein meat alternative derived from fungi. Typically found in brands like Quorn, mycoprotein is a great addition to your diet, containing other nutritional benefits such as high in fibre and low in fat, cholesterol, sodium, and sugar [8].
Do you need to supplement protein?
For the majority of adults, it is possible to get enough protein simply through your diet and most adults in the U.K. are consuming sufficient amounts [1]. There is a common misconception that those following a vegan or a plant-based diet will struggle to meet the recommended intake, however, when following a well-planned, varied diet, it is certainly possible!
Protein supplementation, for example shakes and bars, are a convenient way to increase your intake throughout the day or provide a ‘post-workout’ after a session in the gym. However, it’s important to consider the nutrients you miss out on from whole food sources. For example, 100g of salmon provides 20-25g of protein, but it can also provide between 1 and 2.5g of omega-3; a healthy fat that provides lots of evidenced health benefits. It is very unlikely you’d get this from a protein shake or a bar so, typically, a food-first approach is always recommended.
That being said, if you struggle to reach your protein requirements due to time or appetite, a good quality protein powder from a well-known brand can be a brilliant, convenient way to increase your intake.
Beware of the health halo!
The ‘health halo effect’ is a marketing technique used to make a product sound healthier than it actually is. For example, many consumers believe the term ‘organic’ is synonymous with ‘healthy’ when this is not always the case. Similarly, a product marketed to be ‘high in protein’ may just be, but it might also be high in salt, sugar, or fat…or all three! Remember to check the labels to see what other ingredients are listed. And it may not be particularly high in protein either! For example in a Mars ‘Protein’ Bar you get 10g protein which is higher than in a normal Mars (4.5g) but nutritionally it scores poorly compared to 2 eggs (16g).
Top tip: Ingredients in a product are often listed in descending order by weight, so it can be a good idea to check the top three ingredients to see what largely makes up the product.
So now we know the importance of protein in our daily lives, have a think – do you need to increase your intake? Have a look at some of your cupboard staples and see if a tin of beans or a handful of nuts can be added to your regular meals for an extra boost!
Hello, my name is Clem.
I’m an evidence-based, award-winning nutritionist (MSc, RNutr) and workplace wellbeing specialist.
I help organisations and individuals make sense of nutrition to nurture their health and wellbeing.
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References
[1] British Nutrition Foundation (2024) Protein. Available at: https://www.nutrition.org.uk/nutritional-information/protein/ (Accessed: 30 October 2024)
[2] Campbell, B. et al. (2022) International society of sports nutrition position stand: protein and exercise, Journal of the International Society of Sports Nutrition. Doi: https://doi.org/10.1186/1550-2783-4-8
[3] Ribeiro, A.S., Nunes, J.P. and Schoenfeld, B.J. (2019) Should competitive bodybuilders ingest more protein than current evidence-based recommendations?, Sports Medicine, 49(10), pp. 1481-1485. Doi: 10.1007/s40279-019-01111-y
[4] Yanagisawa, Y. (2023) How dietary amino acids and high protein diets influence insulin secretion, Physiological Reports, 11(2), pp. e15577. Doi:
[5] Rizzoli, R. et al (2014). The role of dietary protein and vitamin D in maintaining musculoskeletal health in postmenopausal women: a consensus statement from the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO).. Maturitas, 79 1, 122-32
[6] Trommelen, J. et al. (2023) The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans, Cell Reports Medicine, 4(12), pp. 101324.
[7] Vitale, K. and Getzin, A. (2019) Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations, Nutrients, 11(6), pp. 1289. Doi: 10.3390/nu11061289
[8] Finnigan, T.J.A. et al. (2019) Mycoprotein: the future of nutritious nonmeat protein, a symposium review, Current Developments in Nutrition, 3(6). Doi: 10.1093/cdn/nzz021
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