If you ever feel the need to really rip on someone and let out your anger and frustration through fat jokes, use a cat as your target.

Dumb cats will think that you're telling them wonderful things and they will purr and make you feel better about yourself anyway...  Smart cats will give you the evil eye and let you know that they are not impressed, which also will give you satisfaction.

Let's try this out.  Test subject, Tiddles.

If she doesn't get fed soon, it won't be just her back paws that disappear. Everything will melt into a pile of jelly rolls.

It works and no one's feelings got hurt!  Win, win!  AND Tiddles got some attention on top of it!