How much protein do you actually need?
The gap between the government minimum and what the training literature supports is bigger than most people realise — and neither number is the one on your tub.
CalculatorProtein TargetOpen →Ask three sources how much protein to eat and you’ll get three answers that differ by a factor of three. The official floor sits near 0.8 g per kilogram of bodyweight. 3 It is worth knowing what that number is and is not: it is the amount at which nitrogen balance studies found most healthy adults stop losing protein — a threshold for avoiding deficiency, not an amount optimal for anything. It was also rounded down from 0.83, and later work using different methods has argued it is set too low, particularly for older adults. Treating it as a target rather than a floor is the single most common misreading of it. Lifting forums say two grams per pound. The supplement label suggests whatever finishes the tub fastest.
All three are answering different questions. The first is the amount that prevents deficiency in a sedentary adult. The second is a bulking-era heuristic that survived because overshooting protein is fairly harmless. Neither is aimed at someone training hard and trying to keep muscle in a deficit.
Start from lean mass, not scale weight
The single most common error is calculating protein from total bodyweight. Two people can weigh the same and carry twenty kilos’ difference in fat, which contributes essentially nothing to protein requirement. Scaling off lean mass fixes this — it’s why our calculator switches to a lean-mass basis the moment you supply a body-fat estimate.
The range that actually matters
For trained individuals in a calorie deficit, the useful band lands roughly between 1.6 and 2.4 g per kilogram of lean mass. Below that, muscle retention suffers during aggressive cuts. Above it, the evidence for additional benefit thins out quickly.
Where the lower figure comes from is worth knowing precisely, because it is quoted everywhere as though it were exact. The meta-analysis pooling 49 trials and 1,863 lifters put the plateau at 1.62 g/kg/day — but with a 95% confidence interval running from 1.03 all the way to 2.20, and the breakpoint itself falling short of conventional statistical significance. 1 The widely repeated “1.6” is the centre of a wide interval, not a threshold. That is precisely why a band is the honest way to express this and a single number is not.
Two further caveats from the same paper. The benefit shrank with age and was larger in already-trained lifters. And the senior author declares grant support and honoraria from the US National Dairy Council, which funded trials included in the analysis — a conflict we disclose here on the same footing as the ones noted in our creatine article, because the standard should not move depending on which way it points.
- Maintenance or a small surplus: the lower half of the range is sufficient.
- Aggressive deficit: push toward the top — protein needs rise as calories fall.
- Older trainees: anabolic resistance means the floor moves up, not down.
The upper end of that band deserves its own caveat. Figures around 2.3 to 3.1 g/kg of lean mass come from recommendations written for natural bodybuilding contest preparation — competitors driving toward stage-level leanness under sustained deficits. 2 That is close to the most extreme case in the literature, and the authors note they had to write a narrative rather than systematic review because the evidence base was so thin. Useful as an upper bound for someone in a hard cut; not a target for someone training normally.
Distribution matters less than the total
The “30 g per meal absorption limit” is a persistent myth. Your body handles larger single doses fine; the total across the day is what drives outcomes. Spreading intake across three or four meals is convenient and probably marginally better for muscle protein synthesis, but it isn’t the lever people think it is.
Hit the daily number first. Optimise timing afterwards, if ever.
- Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM. 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):376-384.Checked against the original
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr, 2014;11:20.Checked against the original
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press, 2005.Checked against the original
How we reviewed this article
Every factual claim here is sourced to peer-reviewed research, a government or institutional guideline, or a named textbook. Where a claim carries a numbered marker, it links straight to that source below, so you can check the original rather than take our word for it.
This article has not been reviewed by a credentialed professional. It was researched and written from the primary sources listed below, but a reviewer catches things citations cannot — omitted contraindications, misread effect sizes, and questions of emphasis. We would rather tell you that than imply a review that did not happen.
Written and edited by a person. All 3 citations have been opened and checked against the original — that the source exists, and that it supports the specific claim it is attached to.
We revisit articles as the evidence changes. This one was published on August 4, 2026. Spotted an error? Tell us — corrections are logged publicly.
Estimates and general guidance only. This is not medical advice.