I had a friend in yeshiva who would only date fat girls; size 22 and up. People used to tell him he was being petty, and that thin girls could also be pretty, and that he was looking only at externals–but he ignored them.
The truth is, I think it was really his mother’s mishegos. She was maybe 300 lbs. and didn’t want to be jealous of her daughter in law.
Anyway, this guy just kept insisting, and refused to go out with anyone below size 22. He’s still single today in his 40’s; he says he never went out with anyone he was attracted to.