Protein timing

Protein timing is the question of how to spread your daily protein: how much at each meal, whether to eat it evenly, whether to have some before bed and when to eat it around a workout. The daily total matters most. A meal of about 0.4 g per kilogram of body weight is a sound efficiency target, a 40 g bedtime dose works when it adds to the day, and the tight "anabolic window" and the case for perfectly even meals are weaker than their reputation.

Aim for about 0.4 g of protein per kilogram per meal (25–30 g for most adults) across three or four meals, have 20–40 g within a couple of hours of a weight session, and consider a 40 g protein feed before bed if you are older or building muscle and it fits inside your daily total.

What timing can and can't do

Muscle is built from protein in the hours after a meal, so in principle how you split the day's protein could change how much of it ends up in muscle. In practice the evidence for timing is much thinner than for the total. How much protein you need each day, and why it rises with age, is covered under Protein; this page is about splitting that total up.

The per-meal dose: about 0.4 g per kilogram

In older men, muscle building from one meal plateaued at about 0.4 g of high-quality protein per kilogram of body weight, roughly 25–30 g for an average adult. Young men plateaued at about 0.24 g/kg, so 0.4 g/kg is a generous target at any age.^[1] Doubling the protein in one sitting does not double the muscle-building response.^[2] Why older muscle needs the larger dose, and the role of the amino acid leucine, are covered under Leucine.

That plateau is about efficiency, not a ceiling. In 36 young active men, 100 g of protein after exercise produced roughly 20% more muscle building than 25 g over the first 4 hours and about 40% more over the next 4–12 hours; one author worked for a dairy company that had no role in the study.^[3] So the popular claim that you can only absorb 30 g at a meal is wrong: you absorb far more, and the extra is used more slowly rather than wasted.

For older adults, 0.4 g/kg works out at 25–30 g a meal at 65–75 kg and 30–40 g above that. One recent review of protein in ageing puts the per-meal dose that maximises muscle building in older people at 25–30 g (0.4 g/kg).^[4] Three such meals come to about 1.2 g/kg a day, inside the 1.0–1.5 g/kg range suggested for people over 65.

Spreading protein evenly: a reasonable habit, not a finding

Many people eat little protein at breakfast and most of it at dinner. Spreading it over three or four meals is a sensible habit, but the evidence behind it is thin.

It rests mostly on one crossover trial of eight adults, who ate the same daily protein either evenly (about 30 g at each of three meals) or skewed toward a large dinner, for a week each. The even split raised 24-hour muscle building about 25%. Two of the authors were paid speakers for a beef industry association.^[5]

Later work has not backed it up. In a randomised trial of 24 healthy adults aged 65–80, even and skewed patterns produced no difference in muscle building,^[6] and a review of the concept found no long-term trial showing that distribution alone changes muscle mass.^[7]

Bedtime protein: 40 g in older adults, if it adds to the day

Overnight is the longest stretch of the day without food. Protein taken just before sleep is digested and used during the night, and it is the timing strategy with the most direct trials, though they are small.

Young men after evening training. In 16 young men who lifted in the evening, 40 g of casein (a slow-digesting milk protein) 30 minutes before sleep raised overnight muscle building about 22%, a result that only just reached significance.^[8]
Older men. In 48 older men, the effect appeared only at 40 g; 20 g did nothing, with or without added leucine.^[9] What that trial says about leucine is covered under Leucine.
Over 12 weeks. In 44 young men on a lifting programme, a nightly protein drink added to their gains in muscle and strength.^[10] But the drink (27.5 g of protein plus carbohydrate) was compared with a calorie-free placebo, so the trial cannot separate the timing from simply eating more protein and energy.

The benefit shows up when the bedtime dose adds to your daily intake, not when it just moves protein from dinner to later. A long-term benefit in older adults has not been shown. A 40 g bedtime feed on top of three 0.4 g/kg meals puts an older adult at about 1.6–1.8 g/kg a day, above the 1.0–1.5 g/kg range for people over 65. Take it on days when the total allows, or during a deliberate higher-protein phase.

Around a workout: hours, not minutes

Protein most clearly buys muscle when it comes around a resistance session, because training primes the muscle to use it. Pooling 21 trials, 20–40 g of whey around a weight session raised muscle building.^[11] That review's own conclusion favoured taking the whey before the session, but the comparison behind it was indirect, across different studies with different workouts. Whey is fast and complete; a normal protein-containing meal works too.

The old "30-minute anabolic window" does not hold up. In the five trials that randomised people to protein before or after each session for at least four weeks, timing made no difference to lean mass or upper-body strength; the one borderline signal, for leg strength, favoured taking it before. With only five trials this is weak evidence, but none of it supports the idea that sooner after training is better.^[12] Within a couple of hours either side is fine.

Limits and who should be careful

Don't routinely go far past 0.4 g/kg at several meals a day unless you are training around it. A 250–300 g steak carries 60–80 g of protein, well past efficient muscle building and into the range that, in mechanistic studies, pushes blood leucine toward the level that switches on mTOR in macrophages, the immune cells that clear fat from artery walls, and stops them clearing it. That mechanism and its limits are on Leucine.
Past 55, watch the total. Bedtime feeds and extra meals add up. Don't let them hold you at 1.8 g/kg a day or more year after year: in one large cohort that intake tracked with more cardiovascular events and deaths, concentrated in the over-55s (see Protein).
Already frail, with several chronic conditions. In one cohort of such older adults, higher protein tracked with higher mortality; decide intake, bedtime feeds included, with a clinician.
Chronic kidney disease. Timing doesn't change the total. People with kidney disease should not adopt the higher daily targets that bedtime and post-workout feeds add up to; current kidney guidelines suggest about 0.8 g/kg a day in stages 3–5 and, at any stage, avoiding more than 1.3 g/kg if the disease is at risk of progressing.^[13]

What to do

Get the daily total right first, using the targets on Protein.
Split it into meals of about 0.4 g/kg: 25–30 g for most adults, 30–40 g for heavier older adults. Three or four meals is a reasonable habit; don't worry about making them exactly equal.
Have 20–40 g of good protein within a couple of hours of lifting, before or after. A normal meal counts.
Consider 40 g of protein before bed if you are older or in a muscle-building phase, counting it toward your daily total. In the one trial in older men, 20 g did not work.
Skip the 30-minute rush and the 30-gram absorption limit; neither is real.