The official adult reference intake for protein is 0.8 grams per kilogram of body weight per day, and no separate, higher figure has been formally set for people over 65. Yet two influential expert panels have argued that older adults should aim higher, at least 1.0 to 1.2 grams per kilogram in healthy people and 1.2 to 1.5 during illness or recovery. The honest short answer is that the higher numbers are reasonable, biologically motivated proposals, not settled requirements confirmed by long-term trials, and they come with an important exception for advanced kidney disease that headlines tend to omit.
Key points#
- The 0.8 g/kg RDA is a single lifelong value derived mainly from nitrogen balance studies, not from outcomes like strength or mobility.
- The PROT-AGE (2013) and ESPEN (2014) panels proposed 1.0 to 1.2 g/kg for healthy older adults, more during illness, always paired with resistance exercise.
- The main biological rationale is anabolic resistance: aging muscle responds less to a given dose of protein.
- These are expert recommendations built on short-term and mechanistic data; long-term trials tracking function and survival are scarce.
- Advanced kidney disease is a real exception where protein is often lowered, not raised, and it is common and underdiagnosed in older adults.
Why age changes the arithmetic#
Start with the biology, because it is what makes older adults a special case rather than just heavier or lighter versions of younger ones. When a young adult eats a serving of protein, muscle tissue reads the incoming amino acids as a signal and ramps up muscle protein synthesis. In older adults that same signal lands softer. The phenomenon is called anabolic resistance, and it means an identical dose of protein produces a smaller building response than it did when you were younger.
Two practical consequences follow. Older muscle appears to need a larger amount of protein in a single sitting, with enough of the amino acid leucine, to fully switch on synthesis, which moves the focus from the daily total to what actually sits on each plate. And a larger share of ingested protein is siphoned off by the gut and liver before it ever reaches muscle. Put together, these shift the question from "is the intake technically adequate" to "is there enough margin left over to preserve strength." A 2023 review in The Journals of Gerontology treats this reduced sensitivity as the central reason to consider intakes above the RDA.
Where the 0.8 figure actually came from#
The 0.8 g/kg Recommended Dietary Allowance is a single number stretched across the entire adult lifespan. It was built largely from nitrogen balance studies, which pin down the intake at which the body neither accumulates nor sheds protein, and those studies skewed toward younger, healthier people than the ones the higher targets are aimed at.
The deeper limitation is what nitrogen balance measures. It answers a narrow accounting question about protein going in versus nitrogen coming out. It does not measure the things you probably care about most: grip strength, walking speed, the ability to climb stairs, or how well you bounce back from a week in a hospital bed. That gap, between what the RDA was designed to guarantee and what people actually want to hold onto as they age, is precisely the space the newer proposals try to fill.
What the expert panels put on the table#
Two groups have made the case for higher targets, and their numbers land close together.
The PROT-AGE Study Group, writing in the Journal of the American Medical Directors Association in 2013, recommended that healthy older adults aim for 1.0 to 1.2 grams per kilogram per day, rising to 1.2 to 1.5 for those with acute or chronic illness and higher still with severe illness or injury. The ESPEN Expert Group, reporting in Clinical Nutrition in 2014, arrived at closely matching figures: at least 1.0 to 1.2 grams for healthy older people and 1.2 to 1.5 for those who are malnourished or at risk from illness.
Both panels attached the same two conditions that often get lost when the numbers travel. First, protein is meant to work with physical activity, especially resistance training, not as a substitute for it. Second, both singled out advanced kidney disease as a situation that flips the advice, where protein may need to be limited rather than raised.
What the higher targets prove, and what they do not#
The distance between a proposal and a proven requirement is where careful reading earns its keep, and the 2023 Gerontology review is useful because it does not oversell.
It documents a genuine downside to eating too little: in controlled feeding studies of older women, intakes below the RDA came with measurable losses of body cell mass, muscle function, and immune response. That is a solid argument against under-eating protein. It is a weaker argument for pushing everyone well above the RDA, because the same review notes that the extra lean mass from higher intakes shows up mainly in metabolically stressed states, such as deliberate weight loss or a resistance training program, rather than in stable, sedentary life.
Two cautions sit inside the evidence itself. One is kidneys. The review notes that roughly 46 percent of adults over 70 have chronic kidney disease and most do not know it, a large group for whom lower intakes, often around 0.6 to 0.8 grams per kilogram, are commonly advised. A blanket "eat more protein" message can therefore be wrong for a substantial share of the people who hear it, and possibly for you. The other is time horizon. The strongest data speak to muscle biology and short-term measures, not to long-term function, independence, or survival. Large trials that assign older adults to different protein targets for years and then track those hard outcomes remain scarce, which is exactly why the panels issued recommendations instead of the field rewriting the RDA. A smaller recurring theme is meal distribution: spreading protein across the day may support muscle better than concentrating it in one meal, though this too rests on shorter studies.
Reading this as an evidence question#
Zoom out and the picture is narrower than either camp suggests on its own. There is good reason to treat 0.8 g/kg as a floor rather than a comfortable target for many older adults, and there is consistent expert support for something nearer 1.0 to 1.2 grams in healthy older people, with more during illness. What is missing is the long-term outcome evidence that would convert a sensible proposal into a settled rule, and what stays firmly in place is the kidney-disease exception any individual decision has to weigh.
The most useful takeaway is a habit of mind rather than a single number. Protein intake in later life is a judgment made against the full picture of your kidney function, activity level, and overall health, which makes it a conversation with your clinician, not a figure to copy from a headline.
Sources and further reading
Questions and answers
Is 0.8 g/kg enough for an older adult?
For many older adults it is better read as a minimum than a target. The RDA was built from nitrogen balance in younger, healthier people and does not directly measure strength or mobility, which is why expert panels suggest healthy older adults consider 1.0 to 1.2 g/kg.
Should everyone over 65 eat more protein?
Not automatically. The extra benefit is clearest during weight loss, illness, or resistance training, and advanced kidney disease is a common reason to keep protein lower rather than higher. Chronic kidney disease is frequent and often undiagnosed after 70, so the right target depends on kidney function and health status.
Does it matter how protein is spread across the day?
It may. Because aging muscle needs a larger single dose to fully trigger synthesis, spreading protein across meals rather than loading one meal appears helpful for muscle retention, though this rests on shorter-term studies rather than long-term outcome trials.