From the perspective of a happy (and happy-go-lucky) fat woman, that question is so absurd I can hardly believe anyone asks it. That people do, with seriousness, reminds me once again why being publicly, shamelessly, unshakably fat and happy is an act of both will and bravery.
The associated poll at AOL is yet further reminder:

People would rather be thin and miserable than look like me and be happy. Well. I would take that more personally if I didn't understand that it's because so many people can't imagine the possibility of looking like me and being happy, because they know the power of their own hostile prejudice, at the blunt end of which they wouldn't want to try to live a happy life.
[H/Ts to Shakers Molliecat and SamanthaExplosion.]


