As an Amazon Associate I earn from qualifying purchases
Protein is the one nutrition topic where the gap between what the research says and what people believe is enormous in both directions. Half the gym thinks you need a shake within ten minutes of your last rep or the session was wasted. The other half thinks protein is overrated and eats 40g a day while wondering why nothing changes.
Both are wrong, and the actual answer is refreshingly boring.
The Short Answer
For building muscle, aim for 1.6 to 2.2 grams of protein per kilogram of body weight per day. That range covers essentially everyone training seriously.
For a 70kg person that is roughly 112g to 154g daily. For a 90kg person, 144g to 198g.
If you want one number to stop thinking about it: 1.8g per kg. It sits comfortably in the middle of the useful range and is achievable without eating chicken at every meal.
Where That Range Comes From
The research on this is unusually consistent. Across many studies, protein intake improves muscle gain up to roughly 1.6g per kg per day, after which the additional benefit becomes very small. The upper bound of 2.2g exists as a buffer for people in a calorie deficit, older trainees, and anyone whose bodyweight estimate is rough.
Above that range, extra protein is not harmful in healthy people. It is just not doing much for muscle, and it is displacing carbohydrates that would have fuelled your training.
If you are dieting, go higher
In a calorie deficit your body is more willing to break down muscle for energy. Higher protein protects against that, and it is also the most filling of the three macronutrients. When cutting, sit at the top of the range, around 2.0 to 2.2g per kg.
If you carry a lot of body fat, adjust the maths
Protein requirements track lean mass, not total mass. Someone at 120kg with significant body fat does not need 240g of protein. Calculate from your target weight or your estimated lean mass instead, which usually lands people 30 to 50g lower.
The Anabolic Window Is Not Real (Mostly)
The idea that you must consume protein within thirty minutes of training has been thoroughly tested and mostly dismantled. The window is more like several hours wide, and what actually matters is your total intake across the day.
If you trained fasted first thing in the morning, sure, eat reasonably soon afterwards. Otherwise, hit your daily number and stop setting timers.
Distribution Does Matter A Little
Here is the nuance worth keeping. Muscle protein synthesis responds to a dose of protein and then plateaus, so spreading intake across the day works slightly better than one enormous meal.
Practically: three to four meals containing 30 to 40g of protein each. That is enough to maximise the response at each sitting without turning your day into a logistics exercise.
One 150g protein dinner and nothing else is worse than four 35g meals. Not catastrophically worse, but measurably.
What 30g Of Protein Actually Looks Like
Numbers on a page are useless until you can see them on a plate.
- 100g cooked chicken breast: around 31g
- 130g cooked lean beef: around 33g
- 150g cooked salmon: around 31g
- 5 whole eggs: around 30g
- 200g Greek yoghurt: around 20g
- 250g cottage cheese: around 28g
- 1 scoop whey protein: around 24g
- 200g cooked lentils: around 18g
- 150g firm tofu: around 17g
- 100g dry oats: around 13g
Most people underestimate how much whole food it takes. That is usually the real problem, not the timing.
Do You Need A Protein Shake?
No. You need protein, and a shake is one convenient way to get some of it.
A shake makes sense if you struggle to hit your number from food, if you train at awkward times, or if you simply do not want to cook a fourth meal. It is a convenience product, not a magic one. Whole food brings fibre, micronutrients and actual satisfaction that powder does not.
If you use one, one or two scoops a day slotted around real meals is plenty.
Plant-Based? Two Adjustments
Plant proteins are generally lower in leucine, the amino acid that triggers muscle protein synthesis, and several are incomplete on their own.
Two fixes: aim toward the higher end of the range, around 2.0g per kg, and vary your sources across the day so the amino acid profiles complement each other. Soy, seitan, lentils, legumes and a plant protein blend will comfortably do the job.
Frequently Asked Questions
How much protein do I need to build muscle?
Between 1.6 and 2.2 grams per kilogram of body weight per day. Around 1.8g per kg is a solid default for most people training regularly.
Can too much protein damage your kidneys?
In people with healthy kidneys, high protein intake has not been shown to cause damage. Anyone with existing kidney disease should follow medical advice on this rather than general fitness guidance.
Do I need protein on rest days?
Yes. Muscle repair happens over several days after a session, not just on training days. Keep your intake consistent across the week.
Is it possible to build muscle on low protein?
Some, but you leave results on the table. Protein is the raw material. Training provides the signal, and without adequate material the signal has less to work with.
Working out your numbers is the easy part. Building meals you will actually eat around a real schedule is where most people come unstuck. Our nutrition and wellness guidance handles exactly that. Talk to a coach to get a plan that fits your kitchen and your week.