Protein is a key nutrient in any balanced diet and is one of the main building blocks of the body. Guidelines on how much you need though, can often differ. The right amount can depend on many factors like age, gender, weight, physical activity as well as health goals. With all these variables no-one’s needs are exactly the same, yet by understanding your body a little more you’ll be able to determine how much protein is right for you in your daily diet.

Minimum protein needs of a healthy adult

Official nutrition guidelines recommend a fairly modest protein intake of about 0.8 g per kg of body weight per day which should be considered the minimum.  This means that healthy men or women weighing 70 kg and living a sedentary lifestyle require at least 56 g of protein per day (1-3). However, personal goals might push these values up.

Older adults need more protein (but often eat less)

As you get older, not only does your body change, but the amount of protein you need also changes. A process known as an ‘anabolic response’ decreases with age, which means the body does not respond as well to the protein in our food.  In other words, the older you get the more protein you need to consume in order to maintain or (re)gain muscle. When you age you also require more protein to combat inflammatory conditions associated with chronic and acute diseases.  In spite of this increased need, older people tend to eat less protein (4-6).

A healthy individual aged 65 years and above should aim to consume at least 1.0 to 1.2 g of protein per kg of body weight per day. This will support good health, assist in recovery from illness and help maintain physical ability (4, 5, 7, 8). Combining this level of protein intake with exercise is thought to be the best way to maintain healthy muscle, so it’s important to try and stay active as you get older (4, 5, 9).

Eating protein for strength and endurance

Consuming more protein has long been known to aid strength training. So if you regularly lift weights in the gym you’ll already be aware of the benefits (10).

However, dietary protein is also important for endurance athletes like runners or cyclists as it helps the body adapt to training as well as being an aid to recovery (11-16).

International exercise guidelines recommend a daily protein intake of 1.4 – 2.0 g per kg of body weight, whether your training is for endurance or for more strength -orientated activities (15, 17).

High protein diets for a healthy weight

Lastly, protein also plays a key role in weight management. It’s more satiating than other macronutrients and may result in lower hunger. It also requires more energy for digestion and processing and helps to maintain muscle tissue during weight loss (18). 

Although no official guidelines exist, research suggests a daily protein intake in the range of 1.2 – 1.6 g per kg of body weight (with 20 – 30 g of protein at each main meal) can support weight loss and prevent weight regain(18-20).

In summary, protein requirements are not the same for everybody but should be tailored to individual needs. If you’re looking to increase your protein intake, it’s vital to understand the dynamics of your body to get the most from this miracle macronutrient.

References

1. FAO/WHO/UNU. Protein and amino acid requirements in human nutrition : report of a joint FAO/WHO/UNU expert consultation. Geneva: World Health Organization; 2007.
2. EFSA Panel on Dietetic Products N, Allergies. Scientific Opinion on Dietary Reference Values for protein. EFSA Journal. 2012;10(2):2557.
3. Wolfe RR, Cifelli AM, Kostas G, Kim I-Y. Optimizing Protein Intake in Adults: Interpretation and Application of the Recommended Dietary Allowance Compared with the Acceptable Macronutrient Distribution Range. Advances in Nutrition. 2017;8(2):266-75.
4. Bauer J, Biolo G, Cederholm T, Cesari M, Cruz-Jentoft AJ, Morley JE, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. Journal of the american Medical Directors association. 2013;14(8):542-59.
5. Deutz NE, Bauer JM, Barazzoni R, Biolo G, Boirie Y, Bosy-Westphal A, et al. Protein intake and exercise for optimal muscle function with aging: recommendations from the ESPEN Expert Group. Clinical nutrition. 2014;33(6):929-36.
6. Lonnie M, Hooker E, Brunstrom JM, Corfe BM, Green MA, Watson AW, et al. Protein for life: Review of optimal protein intake, sustainable dietary sources and the effect on appetite in ageing adults. Nutrients. 2018;10(3):360.
7. Richter M, Baerlocher K, Bauer JM, Elmadfa I, Heseker H, Leschik-Bonnet E, et al. Revised Reference Values for the Intake of Protein. Ann Nutr Metab. 2019;74(3):242-50.
8. Traylor DA, Gorissen SHM, Phillips SM. Perspective: Protein Requirements and Optimal Intakes in Aging: Are We Ready to Recommend More Than the Recommended Daily Allowance? Advances in Nutrition. 2018;9(3):171-82.
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10. Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-84.
11. Churchward-Venne TA, Pinckaers PJM, Smeets JSJ, Betz MW, Senden JM, Goessens JPB, et al. Dose-response effects of dietary protein on muscle protein synthesis during recovery from endurance exercise in young men: a double-blind randomized trial. Am J Clin Nutr. 2020;112(2):303-17.
12. Kato H, Suzuki K, Bannai M, Moore DR. Protein Requirements Are Elevated in Endurance Athletes after Exercise as Determined by the Indicator Amino Acid Oxidation Method. PLoS One. 2016;11(6):e0157406.
13. Moore DR. One size doesn't fit all: postexercise protein requirements for the endurance athlete. Am J Clin Nutr. 2020;112(2):249-50.
14. Vitale K, & Getzin, A. Nutrition and supplement update for the endurance athlete: review and recommendations. Nutrients. 2019;11(6):1289.
15. Jager R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.
16. Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Med Sci Sports Exerc. 2016;48(3):543-68.
17. Kerksick, Wilborn CD, Roberts MD, Smith-Ryan A, Kleiner SM, Jäger R, et al. ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition. 2018;15(1):38.
18. Leidy HJ, Clifton PM, Astrup A, Wycherley TP, Westerterp-Plantenga MS, Luscombe-Marsh ND, et al. The role of protein in weight loss and maintenance. The American journal of clinical nutrition. 2015;101(6):1320S-9S.
19. Phillips SM, Chevalier S, Leidy HJ. Protein "requirements" beyond the RDA: implications for optimizing health. Appl Physiol Nutr Metab. 2016;41(5):565-72.
20. Wu G. Dietary protein intake and human health. Food Funct. 2016;7(3):1251-65.