I'm not a big fan of Mancow's show but you have to respect him for still being able to have one. There is absolutely no reason for the OP. to criticize the man for his physical appearance especially a weight problem that he may be struggling to manage. If you don't like him or his show just say that.
I actually met him at A Roger Waters show a few years back, he bumped into me and spilled my beer and immediately bought me another one, so I have nothing bad to say about the guy.