Does Gretl reward me for eating less?

No, and this is deliberate. There are no streaks to break, no badges, no congratulations for a low day and no scolding for a high one. Nothing in the app treats eating less as a score, because a tracker that rewards restriction is a tracker that teaches it. The only figure Gretl encourages you to reach rather than stay under is fiber, if you turn it on.

If you'd rather not see a target at all, Observe mode (Settings → Goal & Body Stats) tracks everything against nothing — your rings fill as the day goes and there's no number to come in under.