That is a very harmful belief that your friend has. It is unfortunately quite common. I have, though, wrote a few things that people should keep in mind when d

That is a very harmful belief that your friend has. It is unfortunately quite common. I have, though, wrote a few things that people should keep in mind when discussing obesity, elsewhere in this thread. Summarized: Willpower is not a panacea, mind is not above biology; Most people have not conciously chosen to be fat; Ostracizing fat people creates harmful effects and echo-chambers -- constructive criticism is much more effective; Do not forget the part that medical disorders can play in obesity. Of course, this applies only if you actually want to help fat people. If your (not you exactly but people generally) only point is to bully, then the effort of providing constructive criticism is not worth it, the end result being unappealing (i.e. not getting an explosive reaction out of the person you're bullying). In any case, if you want to help, do not approve of such lifestyles (i.e. fat-acceptance), but do not bully. People may need psychological support and even medical in case of an illness. If you want to harm people, just don't.