Partially subverted in The Guild. Clara is overweight, a terrible wife and mother, spends all her time eating, drinking, and abusing her relationships with her friends - but she's also friendliest and probably happiest character, and seems too ditzy to realize that her actions are harmful, even greeting people with hugs and calling Codex her "best friend in the whole wide world".
The stories/art/pictures of popular deviantArt fetish artist Saxxon often feature women who are not only cruel and evil, but almost always inhumanly obese. To put it in perspective, characters who end up rivalling the Earth by the end of the story are amongst the smaller women.
Joe from Statless And Tactless is certainly a bastard (it seems to define him), and Soo calls him a 'fatass' implying he's probably overweight.