Do they think if they insist vehemently enough that they are "beautiful" that will make it so?  That is exactly what they think, yes. It's why you see so many fats talking about their self-acceptance "success story," with that story being, "I saw myself as a horrible disgusting lump of greedy blubber, until I met a horde of other greedy blubber-lumps who told me that blubber-lumps are beautiful and my blubber is beautiful and I should see myself as being beautiful. I was so desperate to be beautiful without any effort that I listened really hard, and now I am convinced my blubber is beautiful! The only thing that spoils it is when someone who isn't a fellow blubber-lump tells me tht my blubber is in fact disgusting and horrible, and reminds me that it is the outward proof of my lazy gluttony. That breaks through the fragile shell of make-believe in which I live and makes me feel awful, like someone has literally torn off my rose-colored glasses. So I cry and run back to the blubber-lump brigade for a refill on my make-believe supply, and after a while i manage to convince myself again that they're right and everyone else is wrong! I feel perfectly beautiful as long as I never, ever venture out of the alternative bubble of blubber-lumps and interact with normal people--here in The Land of Blubber Make-Believe, I can lie to myself all day, while lying to and being lied to by other blubber-lumps just like me! Ta-da! Self-esteem without having to achieve anything! If you simply lie to yourself, anything is possible!"