How much protein you actually need
The honest range is 1.6 to 2.2 grams per kilogram of bodyweight, and almost everything above that number is marketing.
7 min read
Protein is the one part of your diet where getting it right changes the outcome and getting it wrong is quietly expensive. It is also the area where the advice ranges from uselessly low to absurdly high, depending on whether the person telling you has protein powder to sell.
Here is the honest version.
The number
1.6 to 2.2 grams per kilogram of bodyweight per day. In pounds, that is roughly 0.7 to 1 gram per pound.
For an 80 kg person, that is 128 to 176 grams a day. For a 60 kg person, 96 to 132 grams.
That range is not arbitrary. Below about 1.6 g/kg, people in a calorie deficit reliably lose more muscle than they need to. Above about 2.2 g/kg, the additional benefit becomes very hard to detect in studies, even in trained lifters. The range is where the evidence clusters, and the spread within it matters far less than consistently landing inside it.
Why the official recommendation is not the number you want
You may have seen 0.8 g/kg quoted as the recommended daily allowance. That figure is real, but it answers a different question. It is the amount required to prevent deficiency in a sedentary adult — the point below which you start actively breaking down. It is a floor, not a target, in the same way that the minimum wage is not a salary recommendation.
If you are lifting weights, losing fat, or over about fifty, the amount that prevents deficiency and the amount that produces good outcomes are not the same number. The gap between them is most of this article.
Why it matters most when you are eating less
This is the part people skip. When you eat fewer calories than you burn, your body has to make up the shortfall from stored tissue. It does not exclusively take fat. It will take muscle too, and it takes more of it when protein is low.
That has consequences beyond how you look. Muscle is metabolically active, so losing it lowers the number of calories you burn at rest, which makes the deficit harder to maintain and the weight easier to regain. It is the mechanism behind a lot of frustrating rebounds. People lose fifteen kilos, a meaningful share of it lean tissue, and find that maintaining their new weight requires eating less than someone who was always that size.
Higher protein does not prevent this entirely — nothing does — but it substantially reduces it. In deficit conditions, protein is doing more work than in any other circumstance.
The second reason: it keeps you full
Protein is more satiating per calorie than carbohydrate or fat. It also has a higher thermic effect, meaning a slightly larger share of its calories are spent digesting it — roughly 20 to 30 per cent, against 5 to 10 for carbohydrate and 0 to 3 for fat.
The thermic effect is real but small; do not build a strategy on it. The satiety effect is the one that matters. A diet at 2 g/kg protein is meaningfully easier to stick to than the same calories at 1 g/kg, and adherence is the variable that decides whether any of this works.
How to actually hit it
The number looks intimidating until you see it as a per-meal target rather than a daily one. Divide by the number of meals you eat.
At 150 g a day across four meals, that is roughly 35–40 g per meal. In practical terms:
| Food | Portion | Protein |
|---|---|---|
| Chicken breast | 150 g cooked | ~46 g |
| Salmon fillet | 150 g | ~37 g |
| Lean beef mince (5%) | 150 g cooked | ~40 g |
| Eggs | 3 large | ~19 g |
| Greek yoghurt (0%) | 200 g | ~20 g |
| Cottage cheese | 200 g | ~24 g |
| Tofu (firm) | 200 g | ~28 g |
| Lentils, cooked | 200 g | ~18 g |
| Whey powder | 1 scoop (30 g) | ~24 g |
A simple heuristic that works without weighing anything: a palm-sized portion of a protein food at every meal. For most people that lands between 25 and 40 grams, and four of those gets you most of the way there.
If you eat plants
It is entirely achievable, but it takes more deliberate planning, for two reasons.
Plant proteins are generally less concentrated — you eat more total food for the same protein — and most individual plant sources are lower in one or more essential amino acids, particularly leucine, which is the one most directly implicated in muscle protein synthesis. Soy is the notable exception and is complete on its own.
The practical answer is not to obsess over combining proteins at every meal. Eat a variety across the day, lean on the denser sources — soy, seitan, lentils, tempeh, and a plant protein powder if you want one — and aim toward the upper end of the range rather than the lower. Somewhere around 2 g/kg rather than 1.6 is a reasonable adjustment.
Things that do not matter as much as you have been told
Timing. The "anabolic window" — the idea that you must consume protein within thirty to sixty minutes of training — has not held up. Total daily intake matters enormously; the specific clock time matters very little for anyone not training twice a day.
Distribution. Spreading protein reasonably evenly across meals is marginally better than one enormous serving, but the effect is small. Do not skip a meal because you cannot hit an exact number, and do not force a fifth meal you do not want.
The 30 g per meal ceiling. The claim that your body can only "use" about 30 grams at once is a misreading. Absorption is not the constraint; more protein in a single sitting is digested and used, just with diminishing returns. If your schedule means three larger meals, that is fine.
Powder versus food. Whey is a convenient, cheap, well-absorbed protein source. It is not magic and it is not necessary. Nothing happens if you get all of it from food.
When more is not better
There is a persistent belief that very high protein damages the kidneys. In people with healthy kidneys, the evidence does not support this. Intakes well above the range above have been studied without harm to renal function.
That said: if you have existing kidney disease, this changes, and protein intake becomes something to set with a doctor rather than an article. The same applies to some liver conditions. The reassurance above is for healthy adults, and that distinction is not a formality.
The other cost of overshooting is opportunity cost. Calories spent on protein you do not need are calories not spent on carbohydrates that would have fuelled your training, or on the fats you need for hormone production. At some point more protein starts crowding out things you also need.
Does the source matter?
Somewhat, and less than the internet suggests.
Protein quality is usually assessed by the DIAAS or PDCAAS scores, which combine amino acid profile with digestibility. Animal proteins — whey, egg, meat, dairy — score highest. Soy scores well. Most other plant proteins score lower, chiefly because they are limited in one essential amino acid, and because plant cell walls make some of the protein less accessible to digestion.
In practice this matters at the margins. If you are eating well above the minimum, from several sources, across the day, the differences between sources largely wash out. Where it starts to matter is for someone eating a mostly plant-based diet at the lower end of the protein range — there, both the total and the variety need more attention.
The leucine content is the most cited specific factor. Leucine acts as the trigger for muscle protein synthesis, and a meal needs roughly 2.5 to 3 grams of it to produce a strong response. Around 25 to 30 grams of most animal proteins gets you there. Plant sources generally need a larger portion for the same leucine, which is another argument for aiming at the upper end of the range.
Protein as you get older
The requirement goes up, not down, and this is one of the few areas where age genuinely changes the recommendation.
Older muscle exhibits what is called anabolic resistance: the same dose of protein produces a smaller muscle-building response than it would in a younger person. The practical adjustments are to raise total intake toward the top of the range, and to pay more attention to how much lands in each individual meal — somewhere around 30 to 40 grams per sitting rather than a small breakfast and a large dinner.
Combined with resistance training, this is the most effective intervention available against age-related muscle loss, which is among the strongest predictors of losing independence later in life. It is worth taking seriously well before it feels urgent.
What to do
Work out your bodyweight in kilograms, multiply by 1.6 and by 2.2, and treat the result as your window. Aim for somewhere in the middle. Put a palm-sized protein portion at every meal and check what you actually hit for a week — most people discover they are eating considerably less than they assumed.
Then stop thinking about it. Protein is a problem you solve once and then maintain, not one that needs weekly optimisation. The gains from getting it from 0.8 to 1.8 g/kg are large. The gains from getting it from 1.8 to 2.1 are almost invisible, and the time you would spend chasing them is better spent on sleep, training consistency, or almost anything else.