Scale weight is noisy
Day to day, the scale mostly measures water, food in transit, and yesterday's sodium. Swings of a kilo that have nothing to do with fat are completely normal. Reacting to them would mean reacting to noise — so Gravl Macros doesn't.
The trend line
Your trend weight is a smoothed average that gives recent weigh-ins more weight while letting older ones fade. It moves slowly and deliberately, which makes it the number worth watching: when the trend drops, you're actually losing; when a single morning spikes, the trend barely blinks.
The weight chart shows both — your raw scale entries as points, the trend as the line through them. Your rate of change (kg per week) is measured on the trend, not between two arbitrary weigh-ins.
Where your weigh-ins come from
All your sources land in one place: weights logged in Gravl Macros, imported from Apple Health or Health Connect (a smart scale, for example), brought in from another app, and weigh-ins from Gravl Workouts. If the same day has several entries, the app keeps one canonical value per day — a weight you logged yourself takes priority over an automatic import.
Days you don't weigh in are no problem: the trend bridges the gap between your real weigh-ins. More frequent weigh-ins simply make it more responsive.
What it feeds
Trend weight is an input everywhere it matters: the expenditure algorithm reads its movement, the weekly check-in compares it against your goal pace, and your progress screens chart it. One good habit — stepping on the scale regularly, ideally at a consistent time of day — powers all of it.