Not OP, but I work as a waitress as well. Not all rude people are fat, but most fat people Are rude.. and I think it subliminally has to do with shame even if they don't or won't admit it. Being rude gives them the upper hand, or something.. like how the bully in school is always some gross fat person. It's insecurity, and seeing them feed makes them vulnerable. Just my 2cents, it's 6am and I'm barely awake so I'm not sure how much sense this makes.