> I'd eat when I was hungry, and eat enough to stay at my long term stable weight. If I ever stopped tracking every calorie in, my default sense of "full" tende

> I'd eat when I was hungry, and eat enough to stay at my long term stable weight. If I ever stopped tracking every calorie in, my default sense of "full" tended towards a caloric surplus. IIRC, stomachs are fairly elastic, and so can expand. If one consumes/d larger volumes for an extended period of time then that stretch could perhaps become permanent (AIUI), so to actually feel full you have to consume more—which then the rest of one's body has to deal with. It's one of the things that gastric bands can help with, and also sleeve gastrectomy.