Body composition
What the readings support, and no more.
Switch it on and Home gains a Body card: your mass, fat mass and lean mass drawn together, with your training overlaid on the same dates. It is off until you ask for it, and it is careful about what it claims.
Two bands on one axis
The lower band is lean mass, the one above it is fat mass, and the top edge is body mass — the two together. Each band’s height is that tissue’s weight.
Your workouts sit along the top on the same dates, each sized by the energy it burned. So a change in the bands and the training that preceded it are read in one glance instead of two screens.
…and what that shape can mislead you about
Only the lean band is measured from zero. Fat is the gap between the two edges, so how far the fat band sits above the axis means nothing on its own — and because it rides on the lean line, a wobble in lean shifts the whole fat band without any fat having changed.
The app says this on the card itself rather than leaving you to infer it. A chart that can be misread in a specific way should name that way.
It declines rather than guesses
Body-composition readings are noisy, and the honest answer is often that there is not enough signal yet. So the card refuses to state a change the readings cannot support, and says plainly which of these is the problem:
- there are too few weigh-ins to draw a trend from
- the weigh-ins sit too far apart to be comparable
- the most recent one is too old to describe you now
With no body-mass data at all it states that it has nothing to draw, rather than rendering an empty chart that looks like a result.
A number you cannot trust is worse than no number.
Read, shown, and then forgotten
Turning the setting on is what triggers the Health permission request — for body mass, body fat percentage and lean body mass, and for the workouts and active energy drawn beside them. Leave it off and the app requests none of it.
Everything read here is display only. Nothing is saved by the app, synced to your iCloud, or included in its export. And Meter Burn never writes body data to Apple Health — the only thing it ever writes there is the workout itself.
The privacy policy states this in full, including how to revoke access.
See your training against your body.
Free on the App Store · iPhone, iPad and Apple Watch · Requires iOS 26.1. The Apple Watch app requires watchOS 10 and works independently of the phone.