Why older adults need more protein per meal to build and maintain muscle.
What the evidence says
- "Anabolic resistance": older adults mount a blunted muscle-protein-synthesis response to a given dose of dietary protein compared with younger adults[1],[2]
- Older men (~71 y) require ~0.40 g/kg body mass per meal to maximize myofibrillar protein synthesis, versus ~0.24 g/kg for younger men (~22 y) — about 67% more protein per meal relative to body weight[1]
- The age difference is postprandial: basal (fasting) MPS rates do not differ between age groups; the gap appears in the response to a meal[1]
- Older adults are less sensitive to low-protein meals, so suboptimal (low-protein) meals cost them more MPS than they cost younger adults[1]
- Roughly 25–30 g of high-quality protein per meal maximally stimulates MPS in both young and older adults, but responses in the elderly diminish below ~20 g per meal or when protein is taken with large amounts of carbohydrate[2]
- Aging does not inevitably blunt the anabolic response when the per-meal protein threshold is met; leucine supplementation may further support the response in older adults[2]
- Practical emphasis for older adults: distribute adequate protein across meals and hit a higher per-meal dose, rather than relying on total intake alone, to preserve muscle and counter sarcopenia[2]
- Older adults (≥60 y) should consume at least ~1.0 g/kg body weight of protein per day[3]