The short answer
For active people, research supports about 1.6–2.2 grams of protein per kilogram of body weight per day. Sedentary adults need less (~0.8–1.2 g/kg). If you're losing fat or building muscle, aim for the higher end. Get your personal number with the protein calculator.
Why protein matters so much
- Preserves muscle when you're eating in a calorie deficit, so you lose fat, not muscle.
- Builds muscle when you train and eat enough.
- Keeps you full — it's the most satiating macro, which makes any diet easier.
- Has a higher thermic effect — your body burns more digesting protein than carbs or fat.
Timing and distribution
Total daily protein matters most, but spreading it across 3–4 meals of roughly 25–40 grams helps you build and maintain muscle more effectively than loading it all into one meal. Including some protein at breakfast also helps control appetite through the day.
Best protein sources
Animal: chicken, turkey, fish, lean beef, eggs, Greek yogurt, cottage cheese, milk. Plant: tofu, tempeh, lentils, beans, chickpeas, edamame, seitan. Protein powder (whey or plant) is a convenient top-up, not a requirement.
Is too much protein dangerous?
For healthy people, higher-protein diets are safe and don't harm the kidneys. Extremely high intakes simply offer no extra benefit. If you have kidney disease or another medical condition, follow your doctor's advice.
Where the benefit stops
Most protein articles tell you to eat more and stop there. The more useful question is where more stops helping.
A systematic review and meta-analysis published in the British Journal of Sports Medicine pooled data from 49 studies and found that protein supplementation significantly increased strength and lean mass gains from resistance training — and that the benefit appeared to plateau at around 1.6 grams per kilogram of body weight per day.
Two honest caveats. That plateau describes muscle gain in people eating adequate calories; during a calorie deficit, higher intakes look more protective of lean mass, which is why 1.8 to 2.2 g/kg is reasonable when dieting. And a pooled average conceals individual variation — older adults in particular show a blunted response to a given protein dose and may benefit from more.
But if you are forcing down 3 g/kg and finding it a chore, the evidence does not justify the effort. That is worth knowing, because a target you resent is a target you eventually abandon.
Plant protein, properly explained
The claim that plant proteins are "incomplete" is repeated so often it has become received wisdom, and it is more misleading than useful.
Almost all plant foods contain all nine essential amino acids. What varies is the proportions — many plant sources are relatively lower in one particular amino acid, most commonly lysine in grains or methionine in legumes. Soy is a notable exception with a profile comparable to animal protein.
The practical implication is much smaller than the framing suggests. Eating a variety of plant proteins across the day covers the gaps comfortably; the old advice about carefully combining complementary proteins within a single meal has been abandoned, because the body maintains a pool of amino acids and does not require them to arrive simultaneously.
Two genuine adjustments remain. Plant proteins are somewhat less digestible, so aiming perhaps 10–20% higher on total intake is sensible. And plant sources tend to come packaged with more fibre and carbohydrate, which makes hitting a high protein target on a plant-based diet require more deliberate planning — not impossible, just less accidental.
Hitting the target without thinking about it
A target in grams is abstract; portions are not. Roughly speaking, a palm-sized piece of chicken, fish or lean meat gives about 25–30 grams. Three eggs give about 18. A 170-gram pot of Greek yoghurt gives around 17. A 100-gram serving of firm tofu gives about 15, a cup of cooked lentils about 18, and a scoop of protein powder typically 20–25.
Once you know those handful of numbers, hitting 120 grams stops being an arithmetic problem and becomes a structural one: roughly 30 grams at each of three meals plus a snack. Most people who struggle are not failing at dinner — they are eating a breakfast with almost no protein in it, which quietly costs them a third of the day's target before 9am.
Front-loading also helps with appetite. Protein at breakfast is consistently associated with better appetite control through the day, which makes the evening — when most overeating happens — considerably easier to manage.