Bo guide
Short answer
For most adults aiming to preserve or build muscle, 1.6–2.2 g of protein per kg of body weight per day (about 0.7–1.0 g per pound). Sedentary adults need less, around 1–1.2 g per kg.
General information, not medical advice. Written from published sources, which are listed at the end. It is not a substitute for a doctor, pharmacist or registered dietitian who knows your situation.
In this guide7 sections · 3 min
Protein is the one macro worth being precise about, because it is the one that changes what you lose when you lose weight.
The numbers
| Situation | Per kg body weight | Per lb |
|---|---|---|
| Sedentary, general health | 1.0–1.2 g | 0.45–0.55 g |
| Moderately to very active | 1.4–2.2 g | 0.65–1.0 g |
| In a deficit, preserving muscle | 1.8–2.2 g | 0.8–1.0 g |
The high end matters most while cutting. In a calorie deficit your body is looking for tissue to break down, and adequate protein plus some resistance training is what steers that away from muscle.
What the evidence actually says
Two reference points are worth knowing, because they bracket the sensible range.
A large meta-analysis of resistance training studies found that gains in lean mass stopped improving beyond roughly 1.6 g/kg/day. That is the point of diminishing returns for most people, and it is why 1.6 keeps appearing as a target rather than something higher.
The International Society of Sports Nutrition position stand puts the general range at 1.4–2.0 g/kg/day for exercising individuals — and notes that considerably more, 2.3–3.1 g/kg, may be needed to maximise lean mass retention in resistance-trained people during a calorie deficit. So if you are lean, training hard and cutting, the upper end of the table above is a floor rather than a ceiling.
Why it is the macro worth tracking
- It protects muscle in a deficit. Lose weight without enough protein and a meaningful share of it is lean tissue, which lowers your maintenance calories and makes the next cut harder.
- It is the most filling. Gram for gram it does more for satiety than carbohydrate or fat, so hitting it makes the deficit easier to hold.
- It costs energy to digest. Roughly 20–30% of protein calories are burnt processing it, against about 5–10% for carbohydrate and 0–3% for fat. A modest effect across a day, but a real one.
What that looks like in food
Targets are abstract until you see how few foods carry most of the load.
| Food | Portion | Protein |
|---|---|---|
| Chicken breast | 150 g cooked | ~46 g |
| Salmon | 150 g cooked | ~38 g |
| Greek yoghurt (0%) | 200 g | ~20 g |
| Eggs | 2 large | ~13 g |
| Cottage cheese | 100 g | ~11 g |
| Lentils, cooked | 150 g | ~13 g |
| Tofu, firm | 150 g | ~17 g |
| Whey powder | 1 scoop (30 g) | ~24 g |
An 80 kg person targeting 1.8 g/kg needs about 145 g. Chicken at lunch, salmon at dinner and a yoghurt gets you to roughly 105 before breakfast is counted — which is why breakfast is usually the meal that decides whether you hit the number.
Hitting it without effort
Most people undershoot because protein is concentrated in a few foods and absent from most snacks. The fix is structural rather than fiddly:
- Anchor every meal with a protein source and build around it, rather than adding protein as an afterthought.
- Aim for 25–40 g per meal across three or four meals. That gets most people there without counting.
- Fix the weak meal. For most people it is breakfast, and it is the commonest reason a deficit underdelivers. Moving it from near-zero to 30 g often closes the entire daily gap on its own.
- Make snacks count. Greek yoghurt, cottage cheese, a shake — the same calories doing more work.
Plant-based eaters
The targets do not change, but hitting them takes more deliberate planning. Plant proteins are generally lower in leucine — the amino acid that most directly triggers muscle protein synthesis — and individually less complete, so the practical advice is to aim at the upper end of the range and vary sources across the day rather than relying on one.
Soy, seitan, lentils, tofu, tempeh and a pea or soy protein powder between them cover it comfortably. The gap relative to animal protein is real but modest, and it shrinks as total intake rises.
Can you have too much?
For healthy adults, intakes in this range are well tolerated and long-standing concerns about kidney damage have not held up in people with normal kidney function. If you have existing kidney disease, this is a conversation for your doctor rather than an article.
The more practical limit is opportunity cost: every gram of protein is a calorie you are not spending on carbohydrate or fat, and past about 2.2 g/kg you are usually buying very little for it.
