Fats don't stop eating when they are full  And there we go. Thousands of bariatric surgery patients defeat their physical constraints, and keep eating even if it literally kills them, way past the point of fullness. The girl in the article is the opposite. She feels full very quickly, so eats very little, but then feels hungry again soon. So she's constantly grazing. There's nothing that physically stops her from eating past fullness, certainly her stomach is big enough. It's just last of willpower, selfishness and gluttony that drives fats to get and stay fat. There are lots of people who lost weight and keep it off. I did. We're not superhuman. We just don't volunteer for studies, because we don't think we've accomplished anything amazing, we only want to get on with our lives.