It is about control and disdain to a degree. I saw someone here mention r/dyingtobefat and checked it out. It is so disturbing, like watching a snuff film. It's basically one guy getting turned on by how disgusting and useless these fat pigs are getting and talking about how greedy and useless they are and how they're approaching death because they're so fat. None of the fat fetishists I've seen online are fat themselves though.