10-Second Takeaway
- Most people can likely maximize muscle-building benefits around 0.7–0.8 g/lb/day.
- Going higher, up to about 1.0 g/lb/day, can be useful during fat loss, for appetite control, or as a simple safety margin.
- Past that point, more protein usually has a large diminishing return unless there is a specific reason for it.
Core Principle / Mechanism
Protein provides the amino acids your body uses to repair and build muscle tissue. Resistance training creates the signal for adaptation, and protein helps supply the raw material needed to respond to that signal.
Muscle growth does not keep increasing just because protein intake keeps rising. It behaves more like filling a bucket than flipping a magic switch: too little protein leaves potential progress on the table, but once the bucket is mostly full, adding more has less and less impact until, eventually, there’s no impact at all.
The best available evidence suggests that protein intake improves resistance-training gains, but the benefit appears to really start plateauing around 0.7 g/lb/day. Morton et al.¹ found that protein intake beyond roughly 0.7 g/lb/day did not clearly produce further increases in fat-free mass during resistance training. Their confidence interval extended up to about 1.0 g/lb/day, which is why 0.7–1.0 g/lb/day is a useful practical target range.
A larger dose-response meta-analysis by Tagawa et al.² found that lean body mass may continue to improve across a wider range of protein intakes, but the rate of benefit drops sharply once intake passes about 0.6 g/lb/day. That supports the idea that higher protein can still help in some contexts, but the return becomes much smaller once intake is already adequate.
The International Society of Sports Nutrition³ recommends roughly 0.6–0.9 g/lb/day for most exercising individuals, with higher intakes potentially useful during dieting phases or for lean-mass retention.
Decision Rules / Practical Application
- If you want a simple daily target: Aim for at base target that’s anywhere from 0.7–1.0 g/lb/day.
- If you want the practical “enough for most people” target: Aim for 0.7–0.8 g/lb/day.
- If you are dieting, lean, very active, or want extra margin: Aim closer to 0.8–1.0 g/lb/day.
- If you are already above 1.0 g/lb/day: More protein is not the main thing holding back muscle growth. Look at training performance, calories, sleep, recovery, and consistency first.
- If you struggle to hit protein: Do not start by chasing perfection. First, get a solid protein serving at 2–3 meals per day.
- If your protein intake is inconsistent: A slightly lower target you hit consistently is usually better than a high target you only hit occasionally.
- If bodyweight is higher due to body fat: Use a target based on goal bodyweight, lean body mass, or a reasonable adjusted bodyweight instead of forcing protein extremely high based on current scale weight.
Common Mistakes
- Treating 1 g/lb/day as a mandatory minimum instead of the upper end of a useful range.
- Assuming more protein automatically means more muscle.
- Chasing protein so aggressively that carbs, fats, calories, or food quality suffer.
- Using protein intake to compensate for poor training effort, poor sleep, or inconsistent nutrition.
- Ignoring total calories during a muscle-gain or fat-loss phase.
- Thinking the “optimal” number needs to be hit perfectly every single day.
Exceptions & Edge Cases
- Aggressive fat loss phases: Higher protein may help preserve lean mass and manage hunger. Some athletes may benefit from intakes above the normal range during harder cuts.
- Very lean individuals: Leaner individuals dieting toward low body-fat levels may need a higher protein target than someone dieting from a higher body-fat starting point.
- Older adults: Per-meal protein quality and dose may matter more due to anabolic resistance.
- Plant-based diets: Total protein may need to be slightly higher if protein quality, digestibility, or leucine intake is lower.
- Kidney disease or medical restrictions: Protein targets should be individualized with medical guidance.
- Very high bodyweight with higher body fat: Protein targets should usually be based on goal weight or adjusted weight, not automatically current bodyweight.
References
¹ Morton RW, Murphy KT, McKellar SR, 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. British Journal of Sports Medicine. 2018. DOI: 10.1136/bjsports-2017-097608.
² Tagawa R, Watanabe D, Ito K, et al. Dose–response relationship between protein intake and muscle mass increase: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews. 2021. DOI: 10.1093/nutrit/nuaa104.
³ Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition. 2017. DOI: 10.1186/s12970-017-0177-8.