>There's also diet drugs that do this, but they're incredibly dangerous because you can't plug the holes once they're made, you just have to wait for the proteins to break down.

I always wondered if that were a thing. It always seemed to me like an excellent way to burn calories. I grew up and currently live in Vermont where the winters get very very cold and it's well-known that you have to nearly double your caloric intake if you're going to be outdoors in cold temperatures for extended periods of time. Especially doing a vigorous activity like skiing or snowboarding on a blustery day, it's frankly INCREDIBLE the sheer amount of energy the human body can cough up when it's well-fed and the need arises. I tracked myself as burning like 7k calories in a single day once.

Likewise, just going on a short walk can sap an incredible amount of energy from your body if you're not dressed well in poor weather, and it can take several hours and several good meals to get your energy level back up so it's easy to imagine that a significant amount of your body's energy budget goes to keeping you warm.