How big were the 'crash diet' and 'smoke cigarettes to stay thin' and 'use amphetamines to stay thin' industries?

Indeed, we have the inception of Weight Watchers at the start of the next decade, replacing far crazier things like the cabbage diet being used en masse.

Yes, it was easier in some ways to live a healthier life; one reason why was the rampant social policing of each other's weight.