How much protein do you need to build muscle?

Morton et al. 2018 — 49 randomised controlled trials, 1,863 subjects — put the breakpoint for resistance training adaptations at 1.62 g/kg per day, with the confidence interval extending to 2.2 g/kg. One gram per pound of bodyweight is 2.2 g/kg, the top of that interval.

Is 1 gram per pound of protein necessary?

Necessary, no — 1.62 g/kg is where the meta-analytic breakpoint sits and that is about 0.73 g per pound. Defensible, yes: the effect is enhanced by training experience, re-analyses argue the 1.6 figure is under-powered at the upper end, and in a surplus there is no cost to the extra.

Do endurance athletes need less protein?

No, and often more than the general recommendation suggests. Endurance training raises protein turnover and increases oxidation of amino acids during long sessions, and an athlete in an energy deficit needs more protein rather than less to protect lean mass.

Does protein timing matter?

Distribution matters more than timing around a session. Roughly 25 to 35 grams of quality protein clears the leucine threshold and the anabolic response to a meal lasts two to two and a half hours, so the same 180 grams produces a different result across two meals than across four.

Can you eat too much protein?

For healthy kidneys, intakes well above these figures have not been shown to cause harm in the available literature. The practical limit is opportunity cost — protein calories are calories not available for carbohydrate, which matters when your training volume is high.

How Much Protein? What Morton et al. Actually Found

Why the top of the interval

Three arguments, and the third is the one that settles it in practice.

The effect is enhanced by prior training experience. The analysis pooled trained and untrained subjects, and trained subjects showed a larger benefit from higher intakes. If you are trained, the pooled breakpoint understates your requirement.

Re-analyses since 2024 argue the 1.6 figure is under-powered at the upper end. There were fewer studies at high intakes, which widens the interval rather than establishing that the extra is useless.

In a surplus, protein is not competing with anything. This is the decisive practical point. The calories are available. There is no cost to sitting at the upper bound, and the downside risk of being slightly under is larger than the downside risk of being slightly over.

If calories were scarce the calculus would change — protein calories are calories not available for carbohydrate, and carbohydrate fuels training. That is exactly the trade-off that matters for a high-volume endurance athlete.

On a deficit it goes up, not down

1.1 g per pound during a deficit, because protein there is doing a second job.

Two mechanisms. It protects lean mass while energy is scarce — the whole point of eating in a deficit is to lose fat rather than muscle, and higher protein is the strongest dietary lever on that partitioning. And it provides satiety, which matters when you are hungry and adherence is the binding constraint.

Garthe et al. 2013's work on nutritional intervention in elite athletes during weight loss supports the general shape: higher protein plus resistance training preserves lean mass through a deficit that would otherwise cost it.

Distribution matters as much as the total

The same 180 grams produces a different result across two meals than across four.

Roughly 25 to 35 grams of quality protein clears the leucine threshold that maximally triggers muscle protein synthesis, and the anabolic response to a meal lasts two to two and a half hours. ISSN guidance is 0.4 to 0.55 g/kg per meal across three to five meals.

For a 180 lb (82 kg) athlete targeting 180 g:

Distribution	Feeds	Per feed	Verdict
2 meals	2	90 g	Wasteful — well past the threshold, two stimuli
3 meals	3	60 g	Adequate
4 meals	4	45 g	Good
5 meals	5	36 g	Good
6+	6	30 g	Diminishing convenience returns

Four feeds of about 45 g is the practical answer for most people. Base tracks total protein and does not yet track distribution, which is a genuine gap.

Pre-sleep protein is worth its own mention. The overnight fast is the longest window without an anabolic stimulus in the day, and 30 to 40 g of a slower-digesting protein before bed is well supported. For anyone training twice a day this is not a marginal-gains item.

Endurance athletes, specifically

The common belief that endurance athletes need less protein than lifters is wrong, and the reasons compound for a hybrid athlete.

Protein turnover rises with endurance training. More tissue is being repaired.

Amino acid oxidation increases during long sessions, particularly when carbohydrate availability is low — so under-fuelled long sessions burn protein you meant for repair.

Energy deficits are common in this population, and deficits raise protein requirements rather than lowering them.

The failure to watch for: protein getting squeezed to make the calories fit on a peak training week. If that is happening, the calorie target is wrong, not the protein.

What "quality" means

The threshold figures above assume complete protein with a full essential amino acid profile and adequate leucine. Animal sources, dairy, eggs and soy clear it at the quantities listed; most single plant sources need either a larger serving or complementary combining.

This is a real practical difference rather than a marketing one, and it is the main reason a plant-based athlete's protein target is often set 10 to 20% higher.

Can you eat too much

For healthy kidneys, intakes well above these figures have not been shown to cause harm in the available literature. The commonly repeated kidney concern comes from populations with existing renal impairment and does not transfer.

The real limit is opportunity cost. Protein calories are calories not available for carbohydrate. For a lifter at 3 g/kg of carbohydrate that is irrelevant. For an athlete running forty miles a week and needing 6 to 8 g/kg on hard days, protein above about 1 g/lb starts crowding out fuel — and under-fuelled training costs more than the marginal protein returns.

What to do next

Set protein from bodyweight and hold it constant regardless of what else changes in your week. Then check your distribution: if more than half your daily protein arrives in one meal, redistributing it is a free improvement that costs nothing and changes nothing else.

The macro calculator sets all three in the order that lets carbohydrate move with your training.