It's weird how even fatties who believe some people are just naturally genetically fat don't ever seem to at least recognize the option of becoming thin solely as a cold, pragmatic attempt to gain social approval.  Obviously social acceptance is very valuable, and so it's at least worth wondering whether gaining acceptance might be worth the allegedly unhealthy strain you'd put on yourself by keeping yourself "unnaturally" thin.  But they don't even seem to consider the question.  They just seem to "know" they cannot possibly be thin.