Why do you say you have a preference for fat women while it is in fact a fetish?
Do you like your (future) partner to be tall, or have green eyes, or wear suits? If I have a fetish for fat women then surely you must have a fetish for tall men, men with green eyes, or men who are wearing suits. I don't see the difference.
Well, fat women are not the norm, thin women are.
Really? The average clothing size for women in America is a size 16, that's officialy considered ‘overweight’. That would make thin women fall outside of the norm. Yet you don't see guys like me call thin women a fetish. Why do you think that is? It's because we don't judge others based on their appearance and we're not frustrated that people like what they like, and because we experience your prejudice against us every single day; that's why.
People usually follow this up with something like the following: “You're just weird.”, which I think is a typical closing response from someone who has no ammo to shoot anymore because they realize that either they can't win the argument or their reasoning doesn't make any sense after I present them with the facts.