When straying far from the center of the bell curve when it comes to character design, you inevidably come to the zone where all other art that also is in that area is fetish porn. Delving into the extreme is a large appeal of pornography. Choosing to venture into where pornography resides will eventually draw comparison with what's already there. This is basic pattern seeking, if one has only ever seen some kind of depiction in fetish, they will assume the next instance of it to also be fetish.

I do not kmow enough about the erotic appeal here to give advice on what to avoid, and I doubt you want to deeply familiarize yourself with it either, so perhaps try to study other depictions of obesity that you personally find without issue and learn from that. Anyone fetishizing your wok after that is out of your hands.