A physical confirms what Peter and Lois have been fearing all along: Peter is too fat. Instead of trying to get skinny, Peter creates the NAAFP, an advocacy group for the advancement of fat people. Meanwhile, after Lois finds an old picture, she discovers she has a long-lost brother, Patrick. It turns out that Patrick is in a nut house, but Lois gets him out. However, Patrick's hatred of fat people makes him a suspect when a bunch a fat men turn up dead.