I wonder if this is at least partly why some areas of the world have less obesity even though they’re high carb. Sweden, for example. They tend to eat high carb, yet have relatively lower rates of obesity.
My wife’s family, who live in Sweden, just visited. Carb city, multiple meals and snacks. Yet all 4 are thin. When we visited there, we went swimming in the summer in the local river, which runs down from the mountains. That water was freaking cold! And they swim in it near year-round.
And the Swedes start early, taking their babies outside in midwinter, for a long time. They have a saying that there’s no bad weather, only bad clothes.
I’d guess that swimming in ice-cold water 6-9 months a year probably does something.