Guide
How Much Protein to Build Muscle (Per Kg)
The honest answer is less than the supplement industry wants you to think and more than a lot of casual gym advice suggests. For building muscle, most of the research lands on roughly 1.6 to 2.2 grams of protein per kilogram of bodyweight per day. That is the whole game for most people. The rest of this page is about where in that range you should sit, how to split it across the day, and why obsessing over timing is a distraction from the number that actually matters.
THE RANGE
Roughly 1.6 to 2.2 g/kg per day
The most cited work here is a large meta-analysis by Morton and colleagues, which found that protein intakes beyond about 1.6 g/kg of bodyweight per day gave little additional muscle benefit for most trained lifters. The upper bound of the confidence interval reached roughly 2.2 g/kg, which is where the common 'up to 2.2' figure comes from. So if you weigh 80 kg, that is around 128 to 176 grams of protein a day. Sitting anywhere in that band, and hitting it consistently, matters far more than pinning an exact decimal.
WHERE TO SIT
When to aim higher in the range
Push toward the top of the range (roughly 2.0 to 2.2 g/kg) if you are in a calorie deficit and trying to hold onto muscle while losing fat, if you are older, or if you are lean and chasing the last bit of progress. Higher protein is protective when energy is scarce and helps with fullness on fewer calories. If you are eating at maintenance or a surplus and are relatively new to training, the lower end (around 1.6 g/kg) already does almost all the work. There is no meaningful downside to landing a little higher, so if in doubt, aim up rather than down.
COUNTING WHAT
Use lean mass sense-checks if you carry more fat
Protein needs track more closely with lean body mass than total mass, so if you are carrying a lot of body fat, calculating off your full bodyweight can overshoot. A practical fix is to base the number on a target or 'goal' bodyweight rather than your current one, or to use an estimate of lean mass. For most people at a moderate body-fat level this makes little practical difference and the simple bodyweight sum is fine. The point is not precision to the gram, it is a sensible daily target you can actually hit.
PER MEAL
Spread it across three to five meals
Muscle protein synthesis responds to a dose of protein per sitting, and there is a soft ceiling where extra protein in a single meal does less for muscle building. A reasonable working target is roughly 0.4 g/kg per meal, which for an 80 kg person is about 30 to 40 grams, across three to five meals a day. That is one solid protein source per meal: a chicken breast, a tin of tuna, a couple of scoops of whey, Greek yoghurt with some extras, or a decent portion of tofu or lentils. You do not need to be surgical about it. Evenly distributed is slightly better than one giant protein meal, but a lopsided day that still hits your total will build muscle.
TIMING MYTHS
Total over timing: the anabolic window is wide
The idea that you must slam protein within 30 minutes of training or waste the session does not hold up. The so-called anabolic window is more like several hours on either side of a workout, and for anyone who has eaten protein during the day, pre and post training intake blur together anyway. Your daily total is the lever that moves muscle growth. Nail the total, spread it sensibly, and the exact clock time of each meal is a rounding error. Consistency across weeks beats perfect timing on any single day.
IN PRACTICE
Set the target once, then just log against it
The reason people miss their protein is not knowledge, it is friction. This is where a tracker earns its keep. In FORM you set your protein target and log against it without weighing every mouthful: describe a meal in plain English and its AI works out the macros, or scan a barcode against the free Open Food Facts database. You see how your day is stacking up as you go, so you can add a scoop of whey or an extra egg before dinner rather than discovering at midnight that you fell 40 grams short. FORM steers toward the target rather than punishing a miss, and its weekly rebalancing means one low day does not derail the week.
MUSCLE MATH
Protein without the training does not build muscle
Worth saying plainly: protein is the raw material, but progressive resistance training is the signal that tells your body to use it. All the whey in the world will not add muscle without a training stimulus that gradually gets harder over time. FORM is a nutrition and training app in one, so the protein target and the workout that justifies it live in the same place: its generator builds sessions around what you have available and progresses the load automatically as you get stronger. Feed the training, train the muscle, repeat for months. That is genuinely most of it.
FAQ
Frequently asked questions
How much protein do I need per kg to build muscle?
Roughly 1.6 to 2.2 grams per kilogram of bodyweight per day. For an 80 kg person that is about 128 to 176 grams daily. Aim toward the higher end if you are in a calorie deficit, older, or already lean. Hitting the target consistently matters more than the exact figure.
Is there a maximum amount of protein per meal for muscle?
There is a soft ceiling rather than a hard cap. Extra protein in a single meal does progressively less for muscle building, so a practical guide is around 0.4 g/kg per meal (roughly 30 to 40 grams for an 80 kg person) across three to five meals. Going over that is not wasted for other purposes, it just does less specifically for muscle protein synthesis in that sitting.
Do I have to eat protein right after training?
No. The anabolic window is far wider than the old 30-minute claim, more like several hours either side of your session. Your total daily protein is what drives muscle growth. As long as you hit your daily target and spread it reasonably, the exact timing around your workout barely matters.
Will eating more than 2.2 g/kg build extra muscle?
For most trained lifters, no meaningful extra muscle benefit has been shown beyond that range. More protein is not harmful for healthy people and can help with fullness when dieting, but it will not accelerate muscle growth on its own. Your training stimulus, not more protein, is the limiting factor at that point.
How do I actually hit my protein target every day?
Set a fixed daily target and log against it so you can course-correct before the day ends. FORM lets you describe a meal in plain English for AI macros or scan a barcode for free, and it shows your running total so you can top up with whey, eggs, or yoghurt if you are short. Consistency across the week is what builds muscle, not any single perfect day.
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