How Much Protein Do You Need Per Day?

0.8 g/kg is a deficiency floor, not a daily target#

If you want one line on how much protein per day you need: most adults are well served somewhere between 1.2 and 1.6 grams per kilogram of body weight — roughly 85 to 115 grams for a 70 kg person — and the famous 0.8 g/kg figure is the floor of that conversation rather than its conclusion. Train hard or diet hard and the top of the useful range stretches toward 2.0 g/kg. Sit still and simply want to avoid deficiency, and 0.8 genuinely covers you.

The reason there is no single magic number is not that the science is a mess. It is that the science itself reports ranges — a requirement estimate, a training plateau, a recommendation for athletes — and each one arrives with an interval attached that is usually wider than the number it surrounds. Round those into a slogan and you have thrown away the part that told you how much slack you had. So what follows is a band for each situation, and the source that set it.

The RDA is a minimum wearing the wrong name#

Start with the number everyone cites. The Recommended Dietary Allowance for protein — 0.8 grams per kilogram of body weight per day for adults — has been essentially unchanged for more than 70 years, and it was never designed to describe an optimal intake. It was derived from nitrogen balance studies to estimate the minimum amount of protein you must eat to avoid losing body nitrogen, set two standard deviations above the Estimated Average Requirement of 0.66 g/kg so that it covers nearly all healthy people¹.

That is a deficiency threshold, not a performance target. The word "recommended" does the damage: it implies eating 0.8 is the plan and anything above it is excess.

"The protein RDA would more appropriately be termed the 'recommended minimum intake.'" — Wolfe et al., Advances in Nutrition, 2017

The same official framework already admits a much wider window. The Acceptable Macronutrient Distribution Range puts protein at 10–35% of calories, which works out to roughly 1.05–3.67 g/kg/day using reference body weights of 57 kg for women and 70 kg for men¹. So the guidance you have been handed spans more than a threefold range at its edges, and the 0.8 everyone repeats sits below the bottom of it. The precision was never there. For how protein sits alongside the other two macros, see macronutrients explained.

The floor itself may be set too low#

Nitrogen balance — measuring nitrogen in versus nitrogen out — is a blunt instrument. It tends to overstate intake and understate losses, which biases requirement estimates downward. When researchers re-ran the question with the indicator amino acid oxidation technique, feeding eight healthy men graded protein intakes and tracking a labeled amino acid, they landed on a mean requirement of 0.93 g/kg/day and a safe (RDA-equivalent) intake of 1.2 g/kg/day — 41% and 50% above the current EAR and RDA respectively².

The caveats are real and worth putting on the record: eight men is a small sample, the protein was fed as crystalline amino acids rather than as food, and the method carries assumptions of its own. One study does not rewrite a national guideline. What it does is point the same direction as everything else here — the floor sits below most people's best intake, and treating 0.8 as the goal is a reading error rather than a conservative choice.

Above the floor, training sets the ceiling#

Resistance training is the only reliable way to make your body ask for more protein, so it sets the top of the range. Pooled across the randomized trials, the extra muscle bought by extra protein stops accumulating at a total intake of about 1.6 g/kg/day — and the confidence interval on that breakpoint runs from roughly 1.0 to 2.2 g/kg/day³, which is why this article hands you a band and not a number. Past about 2.2 g/kg, nothing in the data moves.

That is the whole conclusion a pillar owes you. The trial designs behind it, the size of the effect, the moderators that decide where in the band you personally sit, and the supplement-industry interest declared by one of the paper's authors are all in how much protein to build muscle.

Ranges by goal#

Different goals ask different things of protein, so the range moves. Here is what the evidence actually supports, with the source for each row.

Your situation	Daily range	Evidence
Sedentary, avoiding deficiency	0.8–1.0 g/kg	RDA is a minimum¹
General health, modern methods	1.0–1.2 g/kg	IAAO safe intake 1.2²
Lifting for muscle	1.4–1.6 g/kg (up to 2.2)	plateau ~1.6, CI to 2.2³
Athletes generally	1.3–1.8 g/kg	Phillips & Van Loon 2011
Dieting in a calorie deficit	1.8–2.0 g/kg	Phillips & Van Loon 2011
Over 65, healthy	1.0–1.2 g/kg	Bauer 2013
Over 65, active or ill	≥1.2 to 1.5 g/kg	Bauer 2013

Two rows deserve a note. Athletes get their own numbers because they are not chasing the absence of deficiency but adaptation to training: the consensus recommendation is 1.3–1.8 g/kg/day spread across the day, rising to 1.8–2.0 g/kg/day when calories are restricted to lose fat and lean mass is on the line⁴. Why the deficit pushes protein up is covered in protein for fat loss.

Older adults get their own numbers for a physiological reason: aging muscle responds less to the same dose. The PROT-AGE group recommends at least 1.0–1.2 g/kg/day for healthy people over 65, ≥1.2 for those who exercise, and 1.2–1.5 for most older adults living with acute or chronic disease⁵.

One practical caveat the tables never print: g/kg of which kilograms? If you carry a large amount of fat mass, scaling to total body weight inflates the target, because fat tissue is not what the protein is feeding. Scaling to a goal body weight is the usual workaround, and it is a judgment call rather than a research finding — any calculator that hands back a single gram number has quietly made that call on your behalf.

Can you eat too much?#

The standard worry is kidneys. The evidence in healthy people does not support it. A systematic review and meta-analysis of 28 randomized controlled trials covering 1,358 participants compared higher-protein diets (defined as ≥1.5 g/kg/day, ≥20% of calories, or ≥100 g/day) against lower or normal intakes and found no meaningful difference in glomerular filtration rate — the change-from-baseline comparison came out at a standardized mean difference of 0.11 (95% CI: −0.05, 0.27), which is statistical noise⁶.

The boundary on that claim: it applies to healthy adults. It is not a green light for people with existing kidney disease, where protein restriction can be clinically appropriate — the PROT-AGE authors specifically flag older adults with an eGFR below 30 who are not on dialysis as needing to limit protein⁵. If you have kidney disease or any condition affecting protein handling, that number is your doctor's call, not a blog's.

The real cost of overshooting is not medical, it is opportunity cost. Protein calories are calories. Pushing to 2.5 g/kg buys nothing the research can detect and displaces carbs and fat you might rather have.

The daily total is what matters — not per-meal arithmetic#

Here is where most people waste their effort. The gym folklore that you must hit 30 grams per meal, or catch a post-workout window, does not survive contact with the meta-analyses. A meta-analysis of 23 studies (525 subjects for the hypertrophy analysis) found a small apparent benefit of protein timing that vanished once total daily protein intake was controlled for — total intake was the strongest predictor of the effect, and the authors concluded the results "refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations"⁷.

Timing studies kept finding benefits because the timing group was eating more protein. Control for the daily total and the magic goes away.

This is liberating rather than disappointing. Distribution probably has some small effect at the margins, and spreading protein across meals is a reasonable default — but it is a rounding error next to the question of whether you hit your daily number at all. A perfectly timed 90-gram day still loses to a sloppily timed 130-gram day.

Which makes the daily total the thing worth measuring — and the thing most people quietly miss, because protein is easy to overestimate by eye. A chicken breast is not "about 40 grams" with any reliability; it depends on the actual weight in front of you, and on which food it is in the first place, since protein per calorie varies far more between foods than between brands of the same food — the best protein sources ranks that properly. A target that is itself a band deserves an estimate shaped like one; a food log that reports a single confident gram figure is claiming a precision the underlying nitrogen-balance data never had. Practicalities are in how to track macros and calories together.

And if you are eating in a deficit, the payoff compounds: protein is the macro that best defends muscle and blunts hunger, which is why the range climbs exactly when calories fall (protein and satiety covers the mechanism).

FAQ#

Is 100 grams of protein a day enough?#

It depends entirely on your body weight and goal. For a 70 kg person, 100 g is about 1.4 g/kg — comfortably enough for general health and near the useful range for building muscle. For a 100 kg person it is 1.0 g/kg: above the RDA, but below where the research says training gains plateau. Convert to g/kg before judging any gram target.

Do I need protein immediately after a workout?#

No. Once total daily protein is accounted for, the timing of intake around training shows no independent effect on muscle or strength gains⁷. Eat protein after training if it is convenient. Do not let chasing a window distract you from the daily total, which is the variable that actually predicts results.

Can too much protein damage your kidneys?#

In healthy adults, the controlled evidence says no: 28 RCTs found no meaningful difference in kidney filtration rate between higher- and normal-protein diets⁶. This does not apply to people with existing kidney disease, who should follow medical advice on protein rather than general guidance.

Sources#

This article was researched and drafted with AI assistance and reviewed for accuracy by the BurnWeek team. It is general information, not medical advice. How we research and correct our articles →