This is an officially licensed Family Guy product.
Image is of Peter lifting up his shirt to reveal another t-shirt with "No Fat Chicks" written on it. This actually happens in Family Guy episode Chitty Chitty Death Bang. It is again referenced in Family Guy episode The Fat Guy Strangler where the NAAFP community board reads "No Fat Chicks."
Memorable quote from Family Guy episode The Fat Guy Strangler: "Don't Worry Lois, I'm good at finding people. I was the one who found Bush after Hurricane Katrina." - Peter