For protein per day muscle gain, the meta-analytic consensus lands at roughly 1.6 grams per kilogram of body weight, with diminishing returns up to about 2.2 g/kg. For a 70 kg (154 lb) adult, that is 112 to 154 grams daily, paired with resistance training. Total grams matter, but so does how you split them and how much leucine each meal carries.
To build muscle, most lifters need 1.6 g of protein per kg of body weight per day — about 112 g for a 70 kg person — alongside resistance training. Intakes up to 2.2 g/kg offer marginal additional benefit for some. Beyond that, extra protein does not produce more muscle. Distribution matters: 3–4 servings of roughly 30–40 g, each supplying at least ~2.5–3 g of leucine, stimulates muscle protein synthesis more effectively than the same total spread too thin.
How Much Protein for Muscle Gain Per Day
The figure most strength researchers converge on is 1.6 g/kg/day for maximizing gains from resistance training, with an upper effective ceiling near 2.2 g/kg. A single post-exercise dose above 0.40 g/kg, layered on top of a daily minimum above 1.6 g/kg, has been proposed as the practical target for maximally stimulating muscle protein synthesis (Naclerio & Seijo, 2019). Muscle growth itself is straightforward in principle: hypertrophy occurs when muscle protein synthesis (MPS) exceeds muscle protein breakdown over time.
| Goal | Protein (g/kg/day) | For a 70 kg (154 lb) adult |
|---|---|---|
| General health (RDA, women) | 0.8 g/kg | ~56 g/day |
| Muscle gain — consensus target | 1.6 g/kg | ~112 g/day |
| Muscle gain — upper effective range | 2.2 g/kg | ~154 g/day |
| Popular “0.8 g/lb” advice | ~1.76 g/kg | ~123 g/day |
| Vegan / vegetarian athletes | 1.3–1.7 g/kg | ~91–119 g/day |
The familiar gym-floor rule — roughly 0.8 g per pound of body weight — works out to about 1.76 g/kg, which is higher than the data say you need but not harmful. If counting in pounds keeps you consistent, the slight excess does no damage. The RDA of 0.8 g/kg (about 56 g/day for the 70 kg adult used in the table above, or roughly 46 g for the lighter ~57 kg reference woman the Institute of Medicine modeled in 2005) is a floor for preventing deficiency, not a target for building muscle.
Plant-based athletes sit slightly higher, at 1.3 to 1.7 g/kg, partly to offset lower digestibility and a thinner leucine profile in some plant sources (The Whole U, University of Washington, 2015). For a broader look at how training status changes the math, see our guide to protein for athletes.
Does More Than 2.2 g/kg Build More Muscle?
No. Above roughly 2.2 g/kg per day, additional protein does not produce additional muscle in trained adults. The synthetic machinery saturates; surplus amino acids are oxidized for energy or used elsewhere. The ceiling is consistent across the resistance-training literature, which is why chasing ever-higher numbers is wasted effort and grocery money.
That ceiling applies to muscle growth specifically. There are reasons some people eat more — satiety during a fat-loss phase, for example — but more grams will not translate into more lean mass once you are already at 1.6–2.2 g/kg and training hard.
Daily Protein Intake for Muscle Building: How to Distribute It
Distribution matters because MPS responds to each feeding, then returns toward baseline. Hitting a per-meal threshold several times a day stimulates more cumulative synthesis than the same total protein split into many tiny servings. In practice, four meals of about 40 g beats eight snacks of 20 g, because each 40 g serving clears the leucine threshold that switches synthesis on, while a 20 g serving may not in larger or older adults.
The case for per-meal targeting is strongest with age: the distribution of protein across meals may matter as much as the daily total for preserving muscle mass. Aging blunts the synthetic response to a given dose — a phenomenon called anabolic resistance — so older lifters benefit from larger, leucine-rich servings spread evenly rather than back-loaded onto dinner. We cover this shift in detail in our guide to protein after 40.
A workable template for a 70 kg person aiming at ~120 g/day:
- Breakfast: ~35 g
- Lunch: ~35 g
- Post-training or afternoon: ~25–30 g
- Dinner: ~30 g
Timing around training is less make-or-break than the internet suggests, but the post-exercise window is still a sensible place to land one of your larger servings. The specifics — how soon, how much — are in our piece on protein after a workout.
Why Leucine Per Serving Is the Limiting Factor
Total grams get the attention, but leucine is the amino acid that actually triggers muscle protein synthesis. Leucine is the primary switch for MPS; a serving needs to deliver roughly 2.5–3 g of it to maximally turn synthesis on. This is why two proteins with identical total grams — even identical PDCAAS scores — can stimulate MPS differently (Applied Physiology, Nutrition, and Metabolism, 2020). Soy and whey demonstrate exactly that gap despite matching on paper.
The leucine-threshold effect is cleanest in head-to-head feeding studies. A 20 g plant-protein blend supplied 1.5 g of leucine — half of an equivalent whey dose — and produced a lower MPS response (0.041 %/h vs whey’s 0.046 %/h). When free leucine was added to bring the plant blend up to 3.0 g, its response (0.049 %/h) became statistically indistinguishable from whey (0.046 %/h). The gap was leucine, not protein source.
The practical takeaway: if you eat lower-leucine plant proteins, either eat a slightly larger serving or combine sources so each meal clears the threshold. Animal proteins generally hit it at a smaller dose because they carry more leucine per gram.
Can You Build Muscle on Plant Protein?
Yes. Plant protein builds muscle when total intake and per-meal leucine are adequate. In an 84-day trial, pea protein (~20–22.5 g/day) and whey produced comparable gains in muscle mass (2.3% vs 2.4%, P = 0.92) and strength, with no significant between-group difference (Nutrients, 2024). The older view that plant proteins cannot support hypertrophy does not survive controlled comparison once dosing is matched.
Potato protein isolate is a useful example. In a McMaster University trial, 25 g of potato protein isolate consumed twice daily effectively stimulated muscle protein synthesis at rest and during exercise recovery in young women — the authors concluded it is a high-quality plant protein. The women who added potato protein increased their synthesis rate; the placebo group did not (McMaster University news release, 2020). Potato protein isolate runs 80–95% protein on a dry basis, and its reported DIAAS has been measured as high as 100%. If you want the full breakdown of the ingredient, see what potato protein is.
What Counts as Quality Here?
Protein quality is measured by PDCAAS and DIAAS, which score how well a protein’s amino acid profile and digestibility match human needs. Animal proteins generally score higher than plant proteins, and egg protein hits a PDCAAS of 1.00 while wheat gluten sits near 0.25. But a high score on a label does not guarantee a high leucine dose in your actual serving — which loops back to why per-meal leucine, not just the score, is what drives the response.
One thing the quality scores do not capture is what else is in the tub. Single-ingredient products sidestep the fillers, gums, and sweetener blends that show up in many powders. For the broader comparison of options, our best protein powder guide lays them out side by side.
References
- Phillips SM. A brief review of critical processes in exercise-induced muscular hypertrophy. Sports Medicine (2014). PMID:24791918
- Murphy CH, et al. Dietary Protein to Maintain Muscle Mass in Aging: A Case for Per-meal Protein Recommendations. The Journal of Frailty & Aging (2016). PMID:26980369
- Burd NA, et al. Anabolic resistance of muscle protein synthesis with aging. Exercise and Sport Sciences Reviews (2013). PMID:23558692
- Lim MT, et al. Muscle Protein Synthesis in Response to Plant-Based Protein Isolates With and Without Added Leucine Versus Whey Protein in Young Men and Women. Current Developments in Nutrition (2024). PMID:38846451
- Oikawa SY, et al. Potato Protein Isolate Stimulates Muscle Protein Synthesis at Rest and with Resistance Exercise in Young Women. Nutrients (2020). PMID:32349353
- Herreman L, et al. Comprehensive overview of the quality of plant- and animal-sourced proteins based on the digestible indispensable amino acid score. Food Science & Nutrition (2020). PMID:33133540
- Ajomiwe N, et al. Protein Nutrition: Understanding Structure, Digestibility, and Bioavailability for Optimal Health. Foods (2024). PMID:38890999
- Schaafsma G. The protein digestibility-corrected amino acid score. The Journal of Nutrition (2000). PMID:10867064
- Devries MC, et al. Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets. The Journal of Nutrition (2018). PMID:30383278
