Strength and muscle

Every strength and muscle claim we've checked against the studies, newest first.

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Evidence check · September 27, 2026 · Grade: Solid

1.6 grams of protein per kilo is a well-supported target for building muscle, even after 55

Across 49 randomized trials, extra protein added muscle to weight training up to about 1.6 grams per kilo of body weight a day, and higher protein helped people keep muscle while losing weight. A new 12-week trial in adults 55 and older found lifting built muscle and strength on a vegetarian or a meat diet, with a little more muscle for the group eating more protein.