Because of its popularity, the demand for both plant and animal-based sources of protein is increasing.¹ Where protein shakes were once considered to be the domain of fitness fanatics, now there is an increasing appetite for protein-rich foods.¹

But is this rise in the interest of dietary protein sources really necessary? How much protein do you actually need? And what happens when you get too much of it? Keep reading to find out.

How much protein should I eat per day?

Most adults need around 0.8–1g of protein per kg of body weight per day. Although, people who are unwell, recovering from an operation, or who have a bad wound may need closer to 1.5g per kg.¹⁶

On average, the UK’s Department of Health recommends that women should eat 45g of protein and men should eat 55.5g of protein each day.¹⁷

It’s worth noting that this doesn’t take individual differences into account, so it’s important to consider your weight in kilograms, your exercise levels and whether you’re recovering from an illness or surgery.¹⁷ For example, if you’re wondering how much protein is needed to build muscle, people who do regular, intensive exercise, including athletes, need to aim for more protein - around 1.2–2g per kg of body weight per day.^5,18This is because, a few studies point out prolonged endurance training sessions can damage and disrupt the muscle being used, meaning that the body needs more protein to be able to repair the muscle and contribute to gains in muscle mass and strength.^19,21

However, whatever your protein requirements, it should be entirely possible to get all the eight essential amino acids you need by eating a wide range of protein-rich food (your body can only make some of these so you must get the complete range from your diet).¹¹ Though of course, if your protein requirements are on the higher end, you may find it easier to reach your protein requirements by using supplements with guidance from a healthcare professional.

What is protein?

Protein is one of the most important macronutrients we need.²Macronutrients are the nutrients we need in larger quantities that provide us with energy – other macronutrients include carbs and fat.³

In fact, there’s growing evidence to suggest that eating protein at or above current dietary regulations may have positive health benefits in certain groups of individuals.¹ As a result, while protein is often emphasised for people who do a lot of exercise, it’s a vital component of any diet.⁴

The good news is that as long as you eat a varied and balanced diet, you’ll usually be able to get all the protein you need.^5-7

To make sure you’re getting enough protein in your diet, you should eat a wide range of different protein sources. Depending on your dietary preferences, you can choose to use animal or plant-based protein sources, including:^8,9

dairy products – one 200ml glass of milk contains 7g of protein or one 120g pot of yoghurt contains 5g of protein
beans and pulses – half a can of lentils or chickpeas contains 10g of protein
fish – one small white fish fillet contains 19g of protein or half a tin of tuna contains 15g of protein
eggs – two eggs contain 12g of protein
meat – 100g of chicken contains 27g of protein and 100g of beef contains 22g of protein
nuts – one tablespoon of peanut butter contains 4.5g of protein or 20g of nuts contains 4g of protein
milk alternatives – one 200ml glass of soya milk contains 6g of protein
tofu – 80g of tofu contains 6.5g of protein
Quorn – 100g of Quorn contains 14g of protein

There are lots of ways to fit protein into your diet – visit our high-protein breakfast ideas or our article on high-protein snacks for more inspiration.

Happy elderly woman celebrating her fitness achievement after a great outdoor workout session, flaunting her strong bicep. Fit senior woman expressing her pride in her successful exercise routine.

What does protein do?

Protein helps us to maintain our health. It’s needed for maintaining or g rowing muscle strength, wound healing, making new cells and repairing old ones, providing energy and helping you fight infections.^10,11

These functions are essential whether you want to support your recovery from intense exercise, prevent muscle wastage or recover from surgery.¹⁰This is because protein is made up of amino acids, which act as building blocks for our bodies.¹²

As a result, protein deficiency is considered to be a form of malnutrition, with symptoms which can include:^13,14,15

unintentional weight loss
brittle hair and nails
a low body weight
fatigue
feeling weak and greater risk of bone fractures
getting ill often and taking a long time to recover

Cropped image of handsome young sportsman making notes while preparing sport nutrition in kitchen at home

Should I take protein supplements?

We live in an extremely busy world which is made even busier when you’re trying to fit in workouts around a job and life. But that’s not the only reason you might struggle to get the amount of protein you need.

For example, if you’re recovering from surgery or dealing with a health condition, preparing enough well-balanced meals to meet your protein intake needs may be difficult.

Thankfully, you don’t have to depend solely on your meals. If you’re looking for quick ways to get extra protein easily or on-the-go, protein supplements may be for you. Convenient protein supplements can include:

shakes – from whey protein shakes to fully plant-based shakes in a variety of flavours, you won’t struggle for choice when you just want to grab a high-protein drink from the fridge or cupboard
powder – whether you’re looking for whey protein, pea protein, legume protein, soy protein or creatine-based protein powders, you’ll be spoilt for choice
bars – with low sugar, low-carb, high-carb, high-protein options available and tasty flavours like chocolate and peanut butter, you’ll never get bored
snacks – if you’ve got a few minutes, grab a handful of wasabi-coated green peas, dark chocolate brazil nuts or brown rice snacks
smoothies – blend your protein powder of choice with fruits and veggies for a delicious powerhouse of nutrition. Use our smoothie recipes as inspiration

Want to find out more? Check out our guide on how to use protein powder.

Can I have too much protein?

In short, yes – too much protein can be bad for you. So, it’s important to stick to consuming the amount of protein recommended for your lifestyle and health profile, rather than simply eating as much as possible.²⁰

If you don’t manage your high-protein diet properly you may have some unwanted effects, such as:

metabolic diseases – some research shows that a high intake of the amino acids associated with protein may contribute to metabolic diseases (such as Gaucher Disease), though this is only thought to happen if the diet is also high in fat. However, the researchers note that larger randomised trials are needed ^22,23
kidney problems – high-protein diets may affect kidney function, particularly if the diet is also low-carb, such as Atkins.²²Short-term high-protein diets may also increase the risk of kidney stone formation²⁴
cardiovascular diseases – if your high-protein diet includes excessive amounts of red meat, eggs and dairy products that are high in saturated fats and cholesterol, you may be at a higher risk for heart disease and other problems^{25, 26}
weight gain – as excess protein is converted to glucose (energy), if you’re not regularly using the glucose through exercise, it can be be stored as glycogen and fat, potentially leading to increased weight gain^22,27

The final say

If you’re looking for convenient ways to increase your protein intake, take a look at our range of protein shakes, protein powders, and protein bars.

But remember, even though protein is an essential macronutrient and having a high-protein intake can have potential health benefits for some people, eating too much protein when you don’t need to may do more harm than good.^1,2,22

Importantly, if you’re thinking of increasing your protein intake, you should consider getting personalised nutrition advice based on your lifestyle from a healthcare professional.

Disclaimer

“This article is for information only. While we strive for accuracy and balance, please be aware that this article may discuss products available for purchase through Holland & Barrett. Food supplements must not be used as a substitute for a varied and balanced diet, and a healthy lifestyle. Consult a healthcare professional before making any health-related decisions.”

Sources

1. Hertzler SR, et al. ‘Plant Proteins: Assessing Their Nutritional Quality and Effects on Health and Physical Function.’ Nutrients. 2020;12(12):3704. Available from: https://doi.org/10.3390/nu12123704.

2. Deer R, Volpi E. Protein Requirements in Critically Ill Older Adults. Nutrients [Internet]. 2018 Mar 20 [cited 2024 Jul 16];10(3):378–8. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872796/

3. Public Health England. Government Dietary Recommendations Government recommendations for energy and nutrients for males and females aged 1 - 18 years and 19+ years [Internet]. [Cited 2024 Apr 16]. Available from: https://assets.publishing.service.gov.uk/media/5a749fece5274a44083b82d8/government_dietary_recommendations.pdf.

4. Wu G. ‘Dietary Protein Intake and Human Health.’ Food & Function. 2016;7(3):1251–65. Available from: https://doi.org/10.1039/c5fo01530h.

5. Egan B. ‘Protein intake for athletes and active adults: Current concepts and controversies.’ Nutrition Bulletin. 2016;41(3):202–13. Available from: https://doi.org/10.1111/nbu.12215.

6. Pim Knuiman, Maria, Verbruggen C, Mensink M. Protein and the Adaptive Response With Endurance Training: Wishful Thinking or a Competitive Edge? Frontiers in physiology [Internet]. 2018 May 23 [cited 2024 Jul 16];9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5974122/

7. Moore DR, et al. ‘Beyond muscle hypertrophy: why dietary protein is important for endurance athletes.’ Applied Physiology, Nutrition, and Metabolism. 2014;39(9):987–97. Available from: https://doi.org/10.1139/apnm-2013-0591.

8. NHS. Protein: A guide to getting the balance right [Internet]. [Cited 2024 Apr 16]. Available from: https://flipbooks.leedsth.nhs.uk/LN002567.pdf.

9. Antonio J, et al. ‘The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals.’ Journal of the International Society of Sports Nutrition. 2014;11(1). Available from: https://doi.org/10.1186/1550-2783-11-19.

10. Venn BJ. Macronutrients and Human Health for the 21st Century. Nutrients [Internet]. 2020 Aug 7 [cited 2024 Jul 16];12(8):2363–3. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7468865/

11. Carbone JW, et al. ‘Dietary protein and muscle mass: Translating science to application and health benefit.’ Nutrients. 2019;11(5):1136. Available from: https://doi.org/10.3390/nu11051136.

12. NHS. The Eatwell Guide [Internet]. [Cited 2024 Apr 15]. Available from: https://www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/the-eatwell-guide/.

13. A healthy balanced diet | British Nutritional Foundation [Internet]. British Nutrition Foundation. 2015 [cited 2024 Jul 16]. Available from: https://www.nutrition.org.uk/creating-a-healthy-diet/a-healthy-balanced-diet/

14. NHS. Eating a Balanced Diet [Internet]. [Cited 2024 Apr 15]. Available from: https://www.nhs.uk/live-well/eat-well/how-to-eat-a-balanced-diet/eating-a-balanced-diet/.

15. NHS. Protein [Internet]. [Cited 2024 Apr 16]. Available from: https://www.hdft.nhs.uk/wp-content/uploads/2015/12/Protein-1.pdf.

16. NHS. The importance of protein in your diet [Internet]. [Cited 2024 Apr 16]. Available from: https://www.berkshirehealthcare.nhs.uk/media/109513434/importance-of-protein-in-diet-bhp220.pdf.

17. Qin P, et al. ‘A review on plant-based proteins from soybean: Health benefits and soy product development.’ Journal of Agriculture and Food Research. 2022;7(7):100265. Available from: https://doi.org/10.1016/j.jafr.2021.100265.

18. NHS. Overview - Malnutrition [Internet]. [Cited 2024 Apr 16]. Available from: https://www.nhs.uk/conditions/malnutrition/.

19. Taylor AK, Cao W, Vora KP, De J, Shieh WJ, Zaki SR, et al. Protein Energy Malnutrition Decreases Immunity and Increases Susceptibility to Influenza Infection in Mice. The journal of infectious diseases (Online University of Chicago Press)/The Journal of infectious diseases [Internet]. 2012 Sep 4 [cited 2024 Jul 16];207(3):501–10. Available from: https://pubmed.ncbi.nlm.nih.gov/22949306/

20. Are you getting enough protein? Here’s what happens if you don’t [Internet]. Uclahealth.org. UCLA Health; 2022 [cited 2024 Jul 16]. Available from: https://www.uclahealth.org/news/article/are-you-getting-enough-protein-heres-what-happens-if-you-dont

21. Ioannis Delimaris. Adverse Effects Associated with Protein Intake above the Recommended Dietary Allowance for Adults. ISRN Nutrition [Internet]. 2013 Jul 18 [cited 2024 Jul 16];2013:1–6. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4045293/

22. Pesta DH, et al. ‘A high-protein diet for reducing body fat: mechanisms and possible caveats.’ Nutrition & Metabolism [Internet]. 2014;11:53. Available from: https://doi.org/10.1186/1743-7075-11-53.

23. Information (US) NC for B. Nutritional and Metabolic Diseases. National Center for Biotechnology Information (US). [Internet]. 1998. Available from: https://www.ncbi.nlm.nih.gov/books/NBK22259/.

24. Asoudeh, F., Talebi, S., Jayedi, A., Marx, W., Najafi, M. T., & Mohammadi, H. Associations of Total Protein or Animal Protein Intake and Animal Protein Sources with Risk of Kidney Stones: A Systematic Review and Dose–Response Meta-Analysis. Advances in Nutrition. 2022. 13(3), 821-832. DOI: https://doi.org/10.1093/advances/nmac013.

25. Hu, F. B. Protein, body weight, and cardiovascular health. The American Journal of Clinical Nutrition. 2023. 82(1), 242S-247S. DOI: https://doi.org/10.1093/ajcn/82.1.242S.

26. Zhang X, Ismail Sergin, Evans TD, Jeong SJ, Rodriguez-Velez A, Kapoor D, et al. High-protein diets increase cardiovascular risk by activating macrophage mTOR to suppress mitophagy. Nature metabolism [Internet]. 2020 Jan 23 [cited 2024 Jul 16];2(1):110–25. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7053091/

27. Hernández-Alonso, P., Salas-Salvadó, J., Ruiz-Canela, M., et al. High dietary protein intake is associated with an increased body weight and total death risk. Clinical Nutrition. 2016. 35(2), 496-506. DOI: https://doi.org/10.1016/j.clnu.2015.03.016.