You should see my '89 year book. Almost no one was even slightly overweight except for the biggest jocks. I see people every day that would have shocked us in the 80s and 90s.

My friend across the street is grossly obese. His best friend just calls him "chubby", but really fat. Told him the guy would have been the fattest kid in my senior class (excepting the jocks).

My theory is this: People keep seeing people bigger than themselves and saying, "I might be fat, but at least I'm not that fat!" Rinse and repeat.