How much protein do you need per day?

The Daily Value for protein on a food label is 50 g a day.

These are the reference amounts used on US food labels and in dietary guidance, not personal targets. What you need shifts with age, pregnancy, medication and health conditions. The % Daily Value shown on every food page here is calculated against the FDA Daily Value for protein, which is 50 g a day.

What this means for you

Fifty grams is the label figure, and most adults in wealthy countries pass it without thinking. A chicken breast is about 55 g on its own. Two eggs, a pot of Greek yogurt and a cup of lentils between them are another 45.

Unsettled. The requirement under that label figure is less settled than one number suggests. Measured the classic way, by nitrogen balance, the average adult needs about 0.64 grams per kilogram a day. Measured with the newer tracer method, about 0.88, roughly a third more. The official US intakes were set in 2005 and have not been revisited since. The review commissioned to check them found the evidence thin: four studies covering pregnancy, seven covering children, six covering adults over 51, and for adults aged 19 to 50 only studies in men.

There is a reason that disagreement has not been settled by pooling everything together. The same review says outright that it cannot be done. Every research group measures the protein requirement a different way, and the differences between the methods make a meta-analysis impossible. That is why two careful reviews of the same question can come back with different numbers, and it is a statement about method rather than about how much protein anybody needs.

Europe uses a different unit for the same idea and lands in a similar place. The European Food Safety Authority puts the adult population reference intake at 0.83 grams per kilogram of body weight a day, which is about 58 g for someone of 70 kg. A reference intake covers almost everyone in a healthy population. It is still not a prescription for the person reading it.

Unsettled. Nobody has set a safe upper limit for protein, and the reason is absence rather than reassurance. EFSA gives no tolerable upper intake level for protein at all. The American review that went looking describes the evidence on an upper level for amino acids as sparse, and says its own scope did not cover the question. So when a high-protein diet is described as having no known ceiling, that is accurate and it means the ceiling was never studied.

There is also a ceiling on what extra buys you. Across 49 randomised trials of resistance training, the gain in lean mass stopped at a total intake of about 1.6 grams per kilogram a day, and the benefit shrank with every year of age. That break point was estimated across trials that differed from each other a great deal, so treat 1.6 as a rough edge and not a line.

So the honest question is not how to eat more protein. It is whether you belong to one of the two groups where more of it does something measurable.

Established. Older adults losing muscle are the clearest case. In ten randomised trials in 1,154 people diagnosed with sarcopenia, whey protein raised muscle mass and walking speed, and raised grip strength when it was combined with resistance training. The training is not an optional extra in those results.

Unsettled. A closer look at that group complicates it. In 21 trials in people over sixty who lift weights, protein supplements added about a quarter of a kilogram of lean mass and small gains in grip and leg strength, while walking, standing and balance tests did not change. In older people already diagnosed with sarcopenia or frailty, protein with exercise beat exercise alone by about 2.6 kg of grip strength, and protein on its own did little. The mass moves more reliably than the movement does.

Myth. For everyone else, the promise on the packet does not survive the trials. An umbrella review of 33 systematic reviews found that when calories are held equal, more protein does not change body weight, fat mass or waist circumference. Whether it helps on a reduced-calorie diet is a question the evidence does not answer cleanly.

Unsettled. The advice to front-load protein at breakfast rests on thinner ground than it sounds. A scoping review pulled together eleven studies of breakfast protein and muscle mass, and about 59 per cent of the findings pointed to more muscle. On muscle strength it was three studies out of six. A scoping review counts studies rather than pooling effects, so those percentages describe a literature and not the size of any benefit, and most of what it counted was observational. The authors asked for randomised trials because there are hardly any.

On the kidney question

In a feeding trial in 164 healthy adults, a diet with a quarter of energy from protein raised kidney filtration rate by about 4 mL/min. The authors were careful about what that means: whether long-term high protein intake leads to kidney disease is uncertain. If you already have kidney disease, protein is a clinical decision rather than a fitness one.

Unsettled. Pooling the randomised trials rather than reading one of them, a high-protein diet raises the kidneys' filtration rate and leaves creatinine where it was, which reads as the kidney working harder rather than failing. Most of those trials were short and judged kidney function from creatinine, so a temporary adjustment and the start of damage look the same in the data. That is why the answer here stays open.

Two questions people ask next, both now answered by trials rather than by opinion.

On plant against animal protein: pooling 30 randomised trials, plant protein built slightly less muscle, with a standardised difference of 0.20. The gap vanished in people over 60, and it vanished between soy and milk protein. Where it persisted was with rice, chia, oat and potato protein. So soy is the plant protein with the evidence behind it, and variety covers the rest.

On timing: spreading protein evenly across meals instead of loading it at dinner made no difference to body composition in a controlled feeding trial during weight loss. The total matters more than the schedule, which is the opposite of what most training advice says.

Written from the evidence cards and the data on this page, then checked back against the sources. Bioma Learn has no human medical reviewer at this time and we say so rather than invent one. Information, not medical advice. How we verify.

Foods highest in protein on this site

• Chicken, broiler or fryers, breast, skinless, cooked — 55.9 g per 1.0 piece (112% DV)
• Chicken, gizzard, all classes, cooked — 44.1 g per 1 cup chopped or dice (88% DV)
• Chicken, breast, cooked, roasted — 43.4 g per 1 cup, chopped or diced (87% DV)
• Chicken, light meat, cooked, roasted — 43.3 g per 1 cup, chopped or diced (87% DV)
• Chicken, cooked, fried — 42.8 g per 1 cup, chopped or diced (86% DV)

All protein sources ranked →

Full guide: Protein: who genuinely needs more of it, and what the extra does not do