Protein and Longevity: Building a Body That Lasts
New research links lifelong protein adequacy to muscle preservation, immune function and graceful aging.
Why protein became the longevity macro
After 40, adults lose roughly 1% of muscle mass per year by default. By 70, the same person who built their identity around being active may struggle to stand from a chair. The single biggest lever against this trajectory is protein — paired with resistance training.
The new minimums
The old RDA of 0.8 g/kg/day was set to prevent deficiency, not optimise function. The current consensus among researchers in muscle metabolism is 1.2–1.6 g/kg/day for healthy adults, and up to 2.0 g/kg/day for older adults or those training hard. Distribute it: 30–40 g of protein at each main meal triggers muscle protein synthesis better than back-loading the day.
Quality matters, but less than you think
Animal proteins are more complete and bioavailable. Plant proteins work too — you just need a bit more total and some variety. Either way, hitting the target consistently beats optimising the source.
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