Call for an urgent rethink of the 'health at every size' concept

When I (AS) was a child, my grandmother used to say "Don't pull an ugly face, because if the wind changes, your face will become stuck like that". I don't know what evidence my grandmother had for this advice, but as a neuroscientist who studies the effects of diet on the hypothalamic control of appetite and body weight, I say "Don't eat an ugly diet or let yourself stay fat, because if the wind changes you may become stuck with permanent obesity." The long-term effects of excess calories and adiposity on body weight regulation appear to have been overlooked in the fat acceptance movement that has emerged in parallel with the obesity epidemic. In this commentary I outline the possibility that excess body fat and its underlying contributors lead to permanent changes in the brain pathways that control body weight, and call for urgent reconsideration of the 'health at every size' concept.