What is lean body mass, and why does it matter as you age?
Lean body mass is everything in your body that isn't fat — muscle, bone, organs and water. It matters more than body weight alone: muscle drives strength, metabolism and glucose handling, and preserving it is one of the strongest protectors of independence and metabolic health as you age. After ~40, muscle is lost gradually unless you actively train and eat to keep it.
Why lean mass beats the scale
Two people at the same weight can have very different bodies — one with more muscle and less fat, the other the reverse. Tracking lean body mass (or the muscle-to-fat balance) tells you whether weight change is muscle or fat, which the scale alone can't. Resistance training plus adequate protein is what builds and preserves it.
How Vita fits in
Vita reads body-composition data from Apple Health (from compatible smart scales) alongside your workouts, and you can add clinical body-composition results from lab reports. Kept next to your Body Age and fitness trends, it helps you see whether you're gaining the kind of mass that supports long-term health.
FAQ
What's the difference between lean body mass and muscle mass?
Muscle mass is one part of lean body mass, which also includes bone, organs and water. In everyday use people track lean mass as a proxy for muscle.
Why does lean body mass matter with age?
Muscle is lost gradually after ~40, and low muscle mass is linked to frailty, falls and worse metabolic health. Preserving lean mass protects strength and independence.
How do I increase lean body mass?
Progressive resistance training plus enough dietary protein is the proven combination; adequate sleep and recovery support the gains.