How much protein do older adults need? More than the RDA

How much protein older adults need, according to the three expert groups that have reviewed the question, is more than the standard adult RDA of 0.8 grams per kilogram of body weight a day. The European Society for Clinical Nutrition and Metabolism, a professional body that issues nutrition guidance for clinicians, recommends at least 1.0 to 1.2 grams per kilogram daily for healthy older people, and 1.2 to 1.5 grams for those who are ill or malnourished [4]. The PROT-AGE study group, an international panel convened by European geriatric medicine societies, reached the same range for people over 65 and advised the upper end for anyone exercising regularly [9]. A third review, looking at adults of all ages, put the target higher still at 1.2 to 1.6 grams per kilogram [3].

Whether eating that much changes anything you can measure is where the evidence splits. A 2022 review pooling 22 studies of 11,332 older adults, average age about 75, found that people eating above the RDA scored better on standard tests of walking speed, leg strength, grip strength and balance [2]. But nine studies that followed 12,424 older adults over time, average age about 85, found no difference at all: those eating more protein lost grip strength and walking speed at much the same rate as everyone else [2].

Measuring people once cannot separate the two explanations. Protein may have kept them strong, or strong and active people may simply eat more protein.

How much protein per meal may matter as much as the daily total. Research on muscle protein synthesis, the process by which the body assembles new muscle protein from amino acids, found that about 25 to 30 grams of high-quality protein in one sitting stimulates it maximally in young and older people alike [5]. Below roughly 20 grams in a meal the response in older adults is blunted, and it is blunted again when the protein arrives alongside a large dose of carbohydrate [5].

Source matters, though less than the supplement aisle suggests. In a trial where 31 healthy men averaging 72 years old ate a controlled diet fixed at the RDA and then added 50 grams a day of extra protein, the share of muscle protein rebuilt each day rose from about 1.46% to 1.59% with whey, and by exactly the same amount with pea protein [1]. Collagen produced no change [1]. Across 16 trials comparing animal and plant protein directly, the two came out level on lean mass and strength in absolute terms, with a small edge for animal protein on lean mass as a share of body weight - and that edge showed up in adults under 50, not in older ones [6].

What people eat decades earlier tracks with how they age. Among 48,762 female nurses followed from midlife into their seventies and eighties, roughly 8 in 100 reached older age free of 11 major diseases and without cognitive or physical impairment [11]. Every 3% of daily calories that came from protein rather than something else went with about 5% better odds of landing in that group, rising to about 38% better odds for protein from plants [11].

Older muscle responds less to the same meal. The effect has a name, anabolic resistance, and it means the muscle-building machinery is harder to switch on at 72 than it was at 25 [1].

In the trial of older men, protein above the RDA was enough to restore signalling that stayed muted at the lower intake, and it did so by raising the amount of amino acids, the building blocks of protein, circulating in the blood after a meal [1]. Collagen, which is short on the specific amino acids muscle needs, produced neither the rise nor the response [1].

Ageing also changes what happens to protein before it ever reaches muscle. The PROT-AGE panel points to higher splanchnic extraction, meaning more of the protein you eat is taken up by the gut and liver and less of it reaches the rest of the body, alongside the low-grade inflammation and illness that break protein down faster in older people [9].

Protein cannot fix the largest part of the problem. Muscle loss with age is driven mostly by the progressive death of motoneurons, the nerve cells that tell muscle fibres when to contract; when one dies, the fibres it controlled waste away unless a surviving nerve takes them over [7]. That is why both panels pair their protein numbers with resistance and aerobic exercise rather than treating the plate as sufficient on its own [4][9].

The firmest evidence here is about what protein does to muscle chemistry over days and weeks. It is much thinner on whether that changes how well people end up living.

• The trial showing that extra protein raised muscle rebuilding ran for eight days in 31 healthy men, all around 72. No women, nobody frail, nobody ill [1].
• The large cohort linking protein to healthy ageing followed female nurses only, and measured diet with food questionnaires, which people fill in imperfectly [11].
• The pooled review found the link to better physical function only in snapshots. When the same authors looked at people followed over years, higher protein did not slow decline [2].

The panel numbers are recommendations assembled from evidence rather than results of a trial that tested them, and the PROT-AGE group says outright that the evidence on protein quality and timing is not yet strong enough to support specific rules [9].

There is one explicit exception. PROT-AGE notes that older people with severe kidney disease who are not on dialysis may need to limit protein rather than raise it, a decision made with a doctor rather than from an article [9]. For people without existing kidney impairment, the 2016 review reports finding no evidence-based link between higher-protein diets and kidney disease or bone harm [3].

For someone weighing 70 kilograms, the panels' range of 1.0 to 1.2 grams per kilogram works out at roughly 70 to 84 grams of protein a day [4][9], against about 56 grams at the standard adult RDA. Split across three meals, that lands near the 25 to 30 grams per sitting that stimulates muscle rebuilding most strongly [5], and the trial in older men added its extra protein at breakfast and lunch rather than stacking it into dinner [1]. What any individual actually needs shifts with kidney function, illness, activity and whether they are losing weight, and the 2025 review of protein needs during weight loss concluded that no trial has directly tested requirements in obesity at all [10].