What is body composition in simple terms?

The share of the body that is fat, muscle, water and bone.

Is body composition the same as BMI?

No. BMI uses only height and weight. Composition separates fat from lean tissue.

How often should I measure it?

Every few weeks under similar conditions makes trends easier to read.

It is an estimate. Use it to track change, not as a single exact number.

Does Visbody measure body composition?

Yes. Visbody M50, M60 and T55 report fat, muscle and water with 8-electrode BIA.

What Is Body Composition? Fat, Muscle and Water Explained

What is body composition?

Body composition describes what the body is made of, not just what it weighs.

Short answer

Body composition is the split of body weight into fat mass and fat-free mass: muscle, water, bone and organs. Two people with the same weight can have very different compositions. It is usually measured with bioelectrical impedance (BIA), which gives an estimate best used to track change over time.

Last updated: November 2026

The main components

Fat mass: stored body fat, including essential fat.
Skeletal muscle: the muscle attached to the skeleton.
Body water: inside and outside the cells.
Bone and other tissue.

Why weight alone is not enough

The scale cannot tell fat from muscle or water. Someone can lose fat and gain muscle and see the same number. Composition shows what changed.

Trainer watching a young man do bicep curls

How it is measured

Bioelectrical impedance sends a very small current through the body and estimates composition from how it flows. Other methods include DEXA and skinfold calipers. BIA gives an estimate, which is most useful for tracking the same person over time.

More electrodes allow readings by segment, such as each arm, each leg and the trunk.

BIA vs 3D scan vs DEXA

Using it with clients

Coaches use composition to set goals, show progress and explain why weight may not move. Reports are for reference, not a medical diagnosis.

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