so, what the hell happened in the 80s and 90s that caused such a large jump? what changed? Diet sodas? super size me? what caused this?
Can we undo this so that we don't need a magic pill?
1) Decrease in physical activity (desk jobs, social media, games, an endless stream of entertainment).
2) Federal subsidies causing a glut of some foods.
3) Increased portion sizes on many things.
4) Forever chemicals, the PFASs, xenoestrogens, bisphenols in many things we touch or what touches our food, messing with our hormones.
5) Hormone-fed livestock for weight gain, does any of that pass on to us?
6) Supranormal stimulation: we're eating and drinking things designed to stimulate us at a level we just weren't evolved to deal with.
7) Real changes in food composition -- as an example, consider the shift from cane sugar to HFCS.
I think that's the most of them. So, imagine each one of them caused a teensy one percent change (caloric intake, increase in digestion efficiency, whatever). Well, that's 1.01 to the power of our seven different factors, or, if you would originally be stable at two thousand calories per day, an extra 144 calories per day. That's about a can of Coke. Doesn't sound like a lot.
However, that adds up to 52,596 extra calories per annum, or a fifteen pound gain. Hideous synergy.
Food got cheap, people got rich, and humans are designed to eat whatever they can see.
200,000 years of living feast to famine tells you "if can get calorically dense food, eat as much as you can, you'll need it later", except your lizard brain never gets the "there's no famine later" message because it's dumb.
Also obesity and wealth are typically inversely correlated within developed countries.
There's more to the story.
And (as sibling comment says) people of more means (say upper-middle class) aren't more obese than poor people. It's more like the opposite.
This is just the myth of the pleasure-button rat extrapolated to humans, which has been debunked in any case.
Americans in the middle income quintile already had easy access to more calories than they should eat in 1960. But boiling another pot of potatoes wasn't as fast or delicious as microwaving another frozen mini-pizza, so there were fewer temptations to overeat.
Video games. Cable TV. More calories. Bigger portions.
Sedentary lifestyles + more food = obesity.
> Can we undo this so that we don't need a magic pill?
Move around and stop eating so much.
But these pills have their place. A lot of people need immediate help getting their weight down and shrinking their appetites.