Sarah Hey offers this bit of Nebraska history, which explains why prior generations didn't deal with so much obesity. Basically, they lived on the edge of starvation!
The superabundance of available food is very recent. We don't do much physical work to get it or to prepare it. My parents didn't grow up with those shiny metallic TV dinners; I didn't grow up with a microwave.
Our brain, accustomed by evolution to scarcity, tells our cells "Hold every calorie! It might be the last one you get for awhile!" It is a message we don't need and possibly the key to pharmaceutical solutions to obesity.
Here on the Northern Plains, where it's single-digit to subzero right now, the thalamus screams, "Oh golly, it's cold, you betcha! Eat more 'cuz it's winter! Produce more fat cells!"
I said that the brain "evolved," didn't I? Or maybe it is just warped. After all, our first act of rebellion against God, the one that cost us a paradise where we could walk around naked and feel good about it, was to eat the one thing not on the diet God gave us.
But the good news is that we have a new diet. Maybe not one that makes us sleek enough to suit our vanity but one that can reverse the chronic effects of an obese ego.
Small portions on this new plan, but they go a long way.