The article goes through why this dramatic increase can not just be due to reduced exercise or increased caloric consumption, but must have some other, unknown factors, to explain it.
https://news.yale.edu/2012/08/02/hunter-gatherers-expend-sam...
https://cebp.aacrjournals.org/content/early/2021/04/13/1055-...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066343/
https://www.nature.com/articles/s41366-020-0586-7
On perusal of the literature, seems that first and second generations are affected as well
Nicotine is an appetite suppressant.
This is in the same category as: sit on the couch watching TV and you're spending almost the same amount of calories as a walking person.
Maybe it also matters how you spend those calories. Fasting helps a lot, westerners don't fast. I assume hunter tribes fast more and also have lots of short bursts of energy.
Some quick googling tells me that walking burns 4x as many calories as sitting. Or maybe I missed your point and you were just claiming that the stated fact is as surprising as this fact would have been had it been true?
So you don't think that people who do more work are "supposed to be" more hungry and thereby eat more food? The people I know who are leaner seem to just not get hungry as often--or as much--as I seem to get... and hell: I've gone through periods where I'm gaining weight and periods where I'm losing weight, and when I'm gaining weight I feel like I'm hungry constantly and when I'm losing weight I find eating a bit tedious.
Except wild animals are also getting obese. I doubt they are becoming less physically active.
There's a tiny bit more context here: https://www.vox.com/2015/8/24/9194579/obesity-animals
As for that article, the author makes a good point it's curious this hasn't been followed-up on.
But yeah I agree with everything you said as well regarding lack of physical exercise.
It varies from country to country. In the UK for instance, calories per household decreased 15-30% from 1980 to 2009 (https://ifs.org.uk/bns/bn142.pdf). The trend has continued since.
The minute I went from college where I was very active to an office job the pounds piled on.
What's interesting is that if you're poor modern Capitalism doesn't allow much free time to exercise, which might explain why the obesity epidemic effects the poor more.
I have a contention with the "obesity hasn't been reversed in any population" claim. Here in Canada, child obesity has in fact decreased in recent years, after several decades of continual increases. Given that childhood obesity, and obesity in general, has been a major social issue everyone is aware of and has been working hard on (I assume), the small decrease in proportion to the amount of energy invested, is rather depressing. Still, maybe cause for some hope.
> Something seems to have changed. But surprisingly, we don’t seem to have any idea what that thing was.
We don't? While exactly how much this is a factor is contended, I thought it was near-consensus at this point that it's because we are less physically active. The timeline certainly fits - beginning about 1890 and ending about 1975 -- that is the period from the beginning to universal adoption of the car.
Between home appliances, powered vehicles and industrial automation, many modern people don't actually have to do anything physical. Hauling their corporeal form between various chairs is literally all the exercise many people get.
This would be unfathomable to my great-grandparents. They walked to the store then hauled the groceries home. They walked a few miles every Sunday to go to church. They walked to work. They tended the fields largely with manual labour and a horse. They mowed the garden and yard, by hand. Every nail in the home, driven by hand. Ground meat for dinner? Minced by hand. And by then, industrialization had already completely changed things for them, to their own grandparents, giving them what they must have thought an amazing amount of free time and leisure. (My great-grandparents clothes were almost certainly machine-woven, for example.)
If we're eating as many calories, or slightly more, as our grandparents did, while barely moving in comparison to them, is it any surprise we all got really fat? In fairness to the paper, I suppose one could view this social change as a mimetic contagion of a sort.