Muscle quality, not just quantity

A person’s metabolic risk depends more on muscle quality and fat distribution (visceral fat and fat infiltration into muscle) than on raw amounts of fat‑free mass. Large imaging‑based cohort analyses show that higher total fat‑free mass can coincide with worse metabolic markers if visceral or intramuscular fat is high, whereas a higher proportion of lean mass (relative to body weight) is protective. — Shifts the conversation from 'build more muscle' to 'assess where fat sits and how muscle is compositionalized,' affecting clinical screening, fitness advice, and obesity‑drug/therapy evaluation.