You've been told 0.8 grams per kilogram. You've also been told 1 gram per pound. Those two numbers differ by a factor of nearly three.

Both are cited by people who sound confident. Neither is wrong, exactly. They're answering different questions.

The reason you can't get a straight answer is that "how much protein" is not one question. It's four, and nobody bothers to ask which one you mean.

The RDA is a floor, and floors are not targets

Start here, because this single misunderstanding causes most of the confusion.

The recommended dietary allowance for protein is 0.8 g per kg of body weight per day. That number was derived from nitrogen balance studies designed to find the intake at which most healthy adults avoid deficiency.

Avoiding deficiency is a low bar. It's the nutritional equivalent of "not currently on fire."

The PROT-AGE study group position paper says this outright for older adults: the 0.8 g/kg recommendation is too low. They recommend 1.0 to 1.2 g/kg/day for healthy older people, and 1.2 to 1.5 g/kg/day for those with acute or chronic illness.

The reason is anabolic resistance. As you age, the same dose of protein produces a weaker muscle-building signal. You need more input for the same output. Their data suggests the per-meal threshold rises with age too, into the 25-30 g range for older adults versus lower thresholds in the young.

So a 70-year-old woman eating "the recommended amount" is quietly under-eating protein by a third.

The four different questions

Here's the fork in the road. Pick your version.

1. "How much so I'm not deficient?" 0.8 g/kg. Done. Almost everyone reading this already clears it.

2. "How much to build or keep muscle while training?" The ISSN position stand on protein and exercise puts it at 1.4 to 2.0 g/kg/day for most exercising individuals.

3. "How much while losing weight?" Higher. The same position stand notes that 2.3 to 3.1 g/kg/day may be needed to maximise retention of lean mass in resistance-trained people during a calorie deficit.

4. "How much past which extra protein does nothing?" The best answer we have is a meta-regression. Morton and colleagues pooled 49 studies with 1,863 participants and found the breakpoint at roughly 1.62 g/kg/day. Beyond that, supplemental protein produced no further gains in fat-free mass.

Notice what that gives you. A practical band of roughly 1.4 to 2.0 g/kg for anyone training, with 1.6 as the point where extra protein stops paying rent for muscle growth specifically.

That's the whole answer for most people. Everything else is refinement.

Convert it once, then stop thinking about it

Weigh yourself in kilograms. Multiply.

Bodyweight Sedentary floor (0.8) Training band (1.6) Fat loss / lean-mass protection (2.2)
55 kg (121 lb) 44 g 88 g 121 g
65 kg (143 lb) 52 g 104 g 143 g
75 kg (165 lb) 60 g 120 g 165 g
85 kg (187 lb) 68 g 136 g 187 g
95 kg (209 lb) 76 g 152 g 209 g

One caveat that matters if you carry a lot of body fat. These numbers scale with total body weight, and fat tissue doesn't need feeding. If your body fat is above roughly 30%, calculate off a target weight or off lean mass instead. Otherwise you'll land on a number that's uncomfortable to eat and doesn't buy you anything.

The 30-gram myth is dead, and it was never quite alive

You've heard it: your body can only use about 20-30 g of protein per sitting, so eating 60 g at dinner wastes half.

That claim came from studies measuring muscle protein synthesis over short windows — typically four to five hours after a dose. Within that window, the response did plateau around 20-25 g.

The problem was the window, not the protein.

Trommelen and colleagues ran the measurement out past 12 hours and compared 25 g against 100 g of protein after resistance exercise. The 100 g dose produced a greater and substantially more prolonged anabolic response. Whole-body protein net balance was higher. Myofibrillar, connective and plasma protein synthesis all rose further.

Their conclusion is blunt: the magnitude and duration of the anabolic response to protein ingestion is not restricted, and has previously been underestimated.

Which means one thing for you practically. If your schedule only allows two big meals, that's fine. Take the daily total and stop apologising for the distribution.

Protein timing: mostly theatre

Now the other myth. The anabolic window.

The story says you have 30 to 60 minutes after training to consume protein or the session is wasted. It sold a lot of shakers.

Schoenfeld and Aragon's meta-analysis on protein timing found that when total daily protein is controlled for, the timing of intake around training has limited independent effect on hypertrophy and strength. Pre-workout and post-workout protein produced similar results across measures.

The apparent timing effect in earlier studies came from a confound. Groups that took a post-workout shake also ate more total protein per day. Control for the total and the timing effect largely evaporates.

So the honest version: eat protein at some point in the several hours around your session. If you had a proper meal two hours before lifting, sprinting to a shake at minute 45 buys you nothing.

Where distribution genuinely does matter: if you're older, or you're in a deficit, or you're eating a low total. Then spreading protein across three or four feedings of 25-40 g each is a reasonable way to make sure the total actually lands. Not because a clock is ticking. Because it's easier to hit 140 g in four meals than to force it into one.

Do this today: the seven-day protein audit

Do not change your diet yet. Measure it first. Almost everyone is wrong about their current intake, in both directions.

Step 1 — Get your target. Bodyweight in kg times 1.6 if you train. Times 2.2 if you're in a deficit and want to keep muscle. Write the number down.

Step 2 — Log three normal days. Don't perform. Eat exactly as you would. Logging changes behaviour, and if you eat "well" for the audit you'll measure a fantasy.

Step 3 — Find your actual daily average. Add the three days, divide by three. Most people land 30-50 g below their target and are genuinely surprised.

Step 4 — Locate the gap by meal. Nine times out of ten it's breakfast. Cereal, toast, fruit, coffee gets you maybe 10 g. That's a 25 g hole opening before 9am that you'll spend all evening trying to fill.

Step 5 — Fix one meal, not all of them. Add a single 30 g protein anchor to the weakest meal. Eggs, Greek yoghurt, cottage cheese, a shake, leftover chicken. One change. Not a diet overhaul.

Step 6 — Learn five foods by heart. You need a rough map, not a database. 100 g chicken breast is around 31 g protein. Three eggs, around 19 g. 170 g Greek yoghurt, around 17 g. 100 g canned tuna, around 25 g. One scoop of whey, 20-25 g. Five numbers cover most days.

Step 7 — Re-audit at day seven. If you're within 15 g of target, you're done. If you're still short by more than 30 g, add a second anchor rather than trying harder at the same meals.

The whole exercise dies at step 2 if logging is annoying, which is exactly why most protein plans fail in week one. Calorie Calculator exists to make the three-day baseline take minutes instead of being the reason you quit.

Why protein helps with fat loss even when calories match

Worth understanding, because it changes how you build meals.

Protein has the highest thermic effect of the three macronutrients. Roughly 20-30% of the calories in protein get spent on digesting and processing it, against about 5-10% for carbohydrate and near zero for fat.

That's not a magic fat burner. On a 150 g protein day it's maybe 120-180 calories. Real, but small.

The bigger lever is satiety and lean mass. Higher protein intakes during energy restriction help preserve resting energy expenditure and protect lean body mass, which is the mechanism that keeps a diet from turning into a slow-motion metabolic slowdown.

And protein is simply harder to overeat. Nobody accidentally consumes 900 calories of chicken breast while watching TV.

If you don't know your maintenance calories yet, the protein number is floating in space. Our TDEE guide walks through how to get a starting estimate, and know your numbers explains what to do with it once you have it.

The kidney question, answered properly

This comes up every time, and it deserves a clean answer rather than a shrug.

A systematic review and meta-analysis in the Journal of Nutrition compared higher-protein diets (defined as at least 1.5 g/kg, or at least 20% of energy, or at least 100 g/day) against normal or lower intakes in healthy adults. When changes in glomerular filtration rate were compared, dietary protein had no effect.

The nuance is important. Higher-protein groups did show higher absolute GFR after the intervention. But that's an adaptive change in filtration rate, not evidence of damage — and the rate of change over time didn't differ.

The important qualifier: this is healthy adults. If you have existing kidney disease, protein intake genuinely is a clinical decision and belongs with your nephrologist, not with a blog.

Plant protein: the part that's actually different

Plant proteins are not inferior in some vague moral sense. They differ in two specific, measurable ways.

Leucine content. Leucine is the amino acid that triggers the muscle-building signal. Plant sources generally carry less of it per gram of protein. The practical fix is a larger dose — roughly 1.2 to 1.5 times the animal-protein serving to hit the same trigger threshold.

Digestibility. Fibre and antinutrients reduce how much of the protein actually gets absorbed. Cooking, soaking and processing narrow the gap considerably. Isolated plant proteins like pea and soy isolate largely close it.

Practical version: if you're plant-based and training seriously, aim toward the upper end of the band, around 1.8 to 2.0 g/kg, and include soy, which has the most complete amino acid profile of the common plant sources.

What actually breaks people's protein intake

Not knowledge. Logistics.

The person eating 70 g when they need 130 g is not confused about the science. They're eating a croissant at their desk because there was nothing else in the house.

Three fixes that work better than motivation:

Cook protein in batches, carbs fresh. Chicken, mince and eggs keep for days. Rice takes 12 minutes. Reverse this and you'll cook nothing.

Keep two zero-effort options in the fridge at all times. Greek yoghurt and cottage cheese require no preparation and no decision. Decisions are the tax that kills adherence.

Anchor the weakest meal, permanently. Not "eat more protein." One specific food, at one specific meal, every day, until it's automatic.

Recovery matters here too. Protein is the raw material, but the adaptation happens when you're not training. Our guide to rest days covers the other half of that equation.

FAQ

How much protein per day to build muscle? Between 1.4 and 2.0 g per kg of bodyweight, per the ISSN position stand. The meta-analytic breakpoint where extra protein stops adding fat-free mass sits around 1.6 g/kg. For a 75 kg person, that's roughly 105 to 150 g per day.

Is 100 g of protein a day enough? It depends entirely on your weight and goal. For a 62 kg person who trains, 100 g is right at the 1.6 g/kg mark. For a 95 kg person trying to hold muscle in a deficit, it's roughly half of what they need.

Can you eat too much protein? For healthy adults, the research doesn't show kidney harm at intakes up to and beyond 1.5 g/kg. The real cost is opportunity cost. Protein calories displace carbohydrate and fat, and if you push protein very high in a fixed calorie budget you may end up under-fuelling training or short on fibre.

Does protein timing matter after a workout? Far less than the supplement industry implied. Meta-analysis shows that once total daily protein is controlled for, timing around the session has limited independent effect. Eat protein somewhere in the hours either side of training and you've captured essentially the whole benefit.

How much protein per meal is optimal? The ISSN suggests roughly 0.25 g/kg per serving, or an absolute 20-40 g. But newer data showing a prolonged response to a 100 g dose means the per-meal ceiling is far softer than previously believed. Distribute for convenience, not because you'll waste protein otherwise.

Do I need protein powder? No. It's food with a lid on it. Powder is useful when whole food is impractical — travel, early mornings, a 25 g gap at 10pm. If you already hit your target with meals, adding a shake adds cost and nothing else.

The one thing to take away

Your protein number is bodyweight in kilograms times 1.6 if you train, times 2.2 if you're cutting, and everything else is a rounding error compared to actually hitting it seven days in a row.

If the honest obstacle is not knowing where you currently land, Calorie Calculator turns the guesswork into a number in a few taps.

— Dolce