You said you couldn't understand what the problem is like. I can only speak for myself, but for myself, the act of attempting to match society's expectations is arduous and humiliating.
For the greater country at large, calories are cheap, nutrition is expensive, cortisol is abundant and exercise is a luxury.
I used to be an exercise bulimic. Now I'm a commuter. When I'm not working I eat about 1300 calories a day.
And I gain weight.