These days, there's one thing interfering with our bodies keeping stable weight. It's the same thing that kept our evolutionary forebears alive through periods of food scarcity and something other animals use to store fat through a period of not eating (bears before hibernating, birds before long distance migration) or for water (marine mammals mostly use metabolic water).

For the full story, have a look at Fructose metabolism as a common evolutionary pathway of survival associated with climate change, food shortage and droughts.

Interestingly, we primates have a larger fructose reaction than most mammals, which the authors trace back to a uricase mutation in the Miocene. There was a starvation die-off. The only survivors had this ability to store lots of fat. Also interestingly (to me, at least) that’s where we lost the ability to synthesize vitamin C.

I’ve read some papers written by Richard Johnson (first author listed) as he was working out how this system works — and that we can generate our own fructose when our electrolytes go out of balance, which ties in with uric acid. But this one lays it out beautifully.

He also had an interview with Peter Attia, which is on Peter’s “Drive” podcast. Worth a listen.

All this said, even with our bodies maintaining a steady weight, we won’t be happy with them.