I have just read with much interest a series of blog posts arguing that the modern obesity epidemic is driven primarily by environmental contaminants that disrupt our bodies' natural weight regulation, which I am not linking because the autobot thinks it is spam. I will attempt to make a comment with the link.

Part of the argument is the claim that humans, barring various rare conditions, simply didn't get particularly fat, no matter what kind of diet they ate, before the industrial age. And that in about 1980 there was a fairly sharp upswing in the rates of obesity worldwide - including among domestic and to some degree wild animals.

Are these claims accurate historically? Were obese people rare in history, and dieting to lose weight essentially unheard of?