No one will change how they view themselves and others if they don't want to, don't make the effort to do so. I think you see that the problem isn't your friend's weight but her attitude and how she views herself and others. I don't know that you can help her any better than you are trying to. I would urge her to get professional help but it doesn't sound like she is interested.

As you have already said, she changed her thinking about being smart/stupid but that she hasn't either changed her weight or her attitude about her looks/weight says, to me, that she could use the professional help, if she will seek it out.