Adipose tissue retains an epigenetic memory of obesity after weight loss

If there really was a gene that allowed you to survive on substantially less food than your peers, pretty much all humans would have said gene. The history of humanity is rife with famine, and that gene would be a game-changer for survival

It's all about tradeoffs. In this case, I wonder if there's an "efficient metabolism" gene that makes your body put a higher percentage of incoming nutrients into long-term storage (mostly in fat tissue). Carriers of this gene would be more likely to survive a famine, but less likely to outrun a predator or defend against an attack by another leaner human, who's genes allocate incoming nutrients to be utilized more effectively in the short-term.

...don't we? According to [0], the amount of food (by energy intake) people get is very diverse worldwide. People can survive famine situations for a long time, and people' problems with obesity is linked to exactly those survival genes.

Granted, some animals are much better at it, crocodiles and bears and stuff can go without food for months.

[0] https://en.wikipedia.org/wiki/List_of_countries_by_food_ener...

I think it’s quite the opposite because it would not be a gene that allows you to survive on less food - it would be a gene that favors replacing glycogen stores over lipid stores. That kind of mechanism would be pretty negative to survival until the modern era of sedentary civilization.

Samoan have a high degree of a particular variant of gene CREBRF that's highly associated with high BMI (see https://doi.org/10.1038/ng.3620). Pop-Sci says it's an adaptation to the life in an island (might also be a founder effect?)

Look into Polynesian peoples. They survived long sea voyages, and are known to be generally large people in modern day. Like the guy at my high school whose nickname was "Big Tonga"