Turning it on
Enable Health sync in your Profile — Apple Health on iPhone, Health Connect on Android (Health Connect must be installed for the toggle to be available). If you declined a permission earlier, your phone's Settings is where it gets re-granted; the app points you there.
What syncs in
Gravl Macros reads weight, height, and body-fat percentage from your health app. That includes measurements other sources put there — a smart scale that writes to Apple Health lands in your Macros weight history automatically, feeding your trend and expenditure like any weigh-in.
Entries that originated in Gravl apps are recognized and skipped on import, so nothing ever counts twice.
What syncs out
Weights, height, and body fat you log in Macros are written back to your health app — and so is your food diary's nutrition: each logged entry exports its calories and a full breakdown (protein, carbs, fat, fiber, sugar, sodium, and more), so other health apps can see your nutrition. Deleting a weigh-in in Macros also removes the entry it had written to your health app; entries you created elsewhere are never touched.
What's deliberately left alone
Health sync doesn't read steps, workouts, active energy, sleep, or heart rate — none of it. Your expenditure comes from your own logging and weight trend, not from a wearable's activity guess. And nutrition is one-way out: food logged directly in other apps isn't imported.
When it syncs
Syncing runs when you open or return to the app, not continuously in the background — if a scale reading seems missing, opening Macros brings it in.