After a year or more they may stop obsessing on food and begin to feel better about themselves. Fat people as a group are no more and no less than thin people as a group. As for healthy eating, the odds are true for both groups. Current research indicates that most people may be fat because of genetic predisposition and a history of dieting. This should not prevent them from quality of and full access to life.
Size discrimination is no laughing matter.
Yet cruel jokes about fat people are tolerated and encouraged. We give tacit permission to anti-fat humor or fat bigotry where we would never allow racist, sexist or homophobic humor. In the late 1800's there were some who tried to bleach the skin of black people so they would appear to look white. In China women used to bind their feet so they'd look small. Some people today believe dieting is akin to skin bleaching and foot binding.