How much protein do you need after 40?

The short answer: most adults over 40 do well aiming for roughly 1.2–1.6 grams of protein per kilogram of body weight per day — noticeably above the official minimum (0.8 g/kg), which was set to prevent deficiency, not to preserve muscle through midlife. If you strength train, the useful range extends toward 2.0 g/kg. For a 75 kg (165 lb) adult, that’s about 90–120 grams a day.

What changes with age

Two curves cross after 40. Muscle becomes less responsive to protein — the same 20-gram dose that triggered muscle building at 30 does less at 60, a phenomenon called anabolic resistance. Meanwhile appetite and total intake tend to drift down. The result: precisely when the body needs more protein to hold muscle, most people eat less of it.

What the evidence supports

Expert groups focused on aging (such as the PROT-AGE consensus) recommend at least 1.0–1.2 g/kg for healthy older adults, with research suggesting more benefit up toward 1.6 g/kg for people who train. Distribution matters more with age: 25–35 grams per meal appears to clear the higher threshold older muscle needs, where the typical pattern — token breakfast, modest lunch, giant dinner — leaves two of three meals below it.

What to do about it

Fix breakfast first; it is almost always the weakest meal. Eggs, Greek yogurt, cottage cheese, leftover dinner — anything that gets the first meal to 25+ grams. Then spread the rest across lunch and dinner rather than loading one. Whole foods first; powder is a convenience, not a requirement.

What we don’t know

The exact ceiling of benefit is unsettled — studies disagree about how much beyond 1.6 g/kg helps, and individual variation is large. Claims of precise per-meal “limits” also overstate the research; totals still dominate.

When to talk to a clinician

If you have chronic kidney disease, protein targets are a medical decision — talk to your clinician before increasing intake. Same if you have a condition affecting appetite or weight loss you didn’t intend.