Protein for muscle: how much you need and when
Most lifters do well on about 1.6 to 2.2 g of protein per kg a day, spread over several meals. Here is what the research says and where the edges are.
Protein gives your body the building blocks to repair and grow muscle after training. Getting enough of it matters, but the useful range is narrower and less extreme than gym folklore suggests. This guide covers daily targets, how to split them across meals, and the situations where your needs change.
How much a day
The International Society of Sports Nutrition (ISSN) position stand recommends 1.4 to 2.0 g of protein per kg of body weight a day for most people who exercise and want to build or keep muscle [1].
The most cited meta-analysis on this question pooled resistance training trials and found that extra protein stopped adding measurable gains in fat-free mass at around 1.62 g per kg a day [2]. The statistical uncertainty around that point ran up to about 2.2 g per kg, so the authors suggested 2.2 g per kg as a sensible upper target for people who want to cover their bases [2].
A practical summary for most lifters:
| Situation | Daily protein (g per kg body weight) |
|---|---|
| Building or keeping muscle | about 1.6, up to 2.2 [2, 7] |
| Range in the ISSN position stand | 1.4 to 2.0 [1] |
| Lean lifters in a calorie deficit | higher, see below [1, 4] |
If you carry a lot of body fat, working from your total body weight can give a very high number. Basing your target on a goal weight or on lean mass keeps it sensible.
Spreading it across the day
How you split protein seems to matter less than the daily total, but there are good reasons to spread it out. The ISSN recommends doses of about 0.25 g per kg of body weight, or 20 to 40 g, of high-quality protein per meal, ideally evenly spaced every 3 to 4 hours [1].
A review of how much protein the body can use in one sitting suggested aiming for about 0.4 g per kg per meal across at least four meals to reach a minimum of 1.6 g per kg a day, and up to about 0.55 g per kg per meal if you are aiming for 2.2 g per kg [3].
In practice, three or four meals, each built around a decent protein source, gets most people there without much thought.
During a cut
Holding on to muscle gets harder when you eat less than you burn, and higher protein is one of the main tools for it [4]. The ISSN notes that intakes of 2.3 to 3.1 g per kg a day may be needed to maximise retention of lean mass in resistance-trained people during periods of low calorie intake [1]. A review written for natural bodybuilders preparing for a contest recommended 2.3 to 3.1 g per kg of lean body mass a day, with the higher end for leaner people and harsher deficits [4].
For the rest of the picture, including how fast to lose weight, see cutting and bulking.
Older lifters
In the meta-analysis above, the extra benefit of protein supplementation on muscle gains got smaller with increasing age [2]. An expert group on protein needs in older people (PROT-AGE) recommended at least 1.0 to 1.2 g per kg a day for people over 65, and 1.2 g per kg or more for those who exercise [5]. For older people who lift, aiming for the same daily range as younger lifters is a reasonable approach, with a solid serving of protein at each meal [1, 2, 5].
Food sources
The ISSN advises getting most of your protein from whole foods that contain all the essential amino acids, with supplements as a practical convenience rather than a requirement [1]. Good options include:
- Meat, poultry and fish
- Eggs
- Milk, Greek yoghurt, skyr and cottage cheese
- Tofu, tempeh and soya milk
- Beans, lentils and chickpeas, especially combined with grains
- Protein powder (whey or plant) when whole food is inconvenient
If you eat mostly plants, mix your sources across the day.
Is high protein safe for your kidneys?
For healthy adults, the evidence is reassuring. A systematic review and meta-analysis of 28 trials compared higher-protein diets (at least 1.5 g per kg a day, or 20% of energy) with normal or lower-protein diets and found no difference in the change in kidney filtration rate (GFR) between them [6]. The authors concluded higher protein intakes did not harm kidney function in healthy adults, while noting the trials had an unclear risk of bias [6].
That conclusion applies to healthy kidneys only. In people with severe chronic kidney disease who are not on dialysis, the PROT-AGE group noted that protein may need to be restricted rather than increased [5]. If you have kidney disease, diabetes affecting your kidneys, or abnormal kidney results on a blood test, ask your doctor before raising your protein intake. See bloodwork for lifters for what those tests mean.
If you have a history of disordered eating, weighing and logging every gram of protein may not help you. A dietitian can help you meet your needs without close tracking.
Tracking it in ETS
The Body tab sets a daily protein target alongside your calories and other macros, using a higher figure per kg when your goal is a cut, and basing it on lean mass if you have entered a body fat percentage. You can check it against your weigh-in trend and training log to see whether your intake is supporting the goal you set.
Sources
- Jäger, Kerksick, Campbell and colleagues. International Society of Sports Nutrition position stand: protein and exercise. Journal of the International Society of Sports Nutrition, 2017. UNC repository
- Morton RW, Murphy KT, McKellar SR and colleagues. 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. British Journal of Sports Medicine, 2018. BJSM
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition, 2018. CUNY Academic Works
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition, 2014. Full text
- Bauer J, Biolo G, Cederholm T and colleagues. 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. McMaster record
- Devries MC, Sithamparapillai A, Brimble KS and colleagues. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets: a systematic review and meta-analysis. Journal of Nutrition, 2018. McMaster record
- Iraki J, Fitschen P, Espinar S, Helms E. Nutrition recommendations for bodybuilders in the off-season: a narrative review. Sports, 2019. MDPI
More on nutrition
Last reviewed 7 October 2026. General information, not medical advice. Found a mistake? Email [email protected].