The evidence for this adaptive thermogenesis is scant and inconclusive. Even if it were true, we're talking about a difference of 100 kcal/day, which doesn't mean one can eat significantly less.

It doesn't make sense that our bodies would be capable of doing this. Evolutionary, if our bodies could do the same tasks for a lower energy expenditure, we'd all do that. But you simply can't keep a body at 37.5°C for half the calories

Possibly this article, or one based on it?

After ‘The Biggest Loser,’ Their Bodies Fought to Regain Weight https://www.nytimes.com/2016/05/02/health/biggest-loser-weig...

Quote:

It has to do with resting metabolism, which determines how many calories a person burns when at rest. When the show began, the contestants, though hugely overweight, had normal metabolisms for their size, meaning they were burning a normal number of calories for people of their weight. When it ended, their metabolisms had slowed radically and their bodies were not burning enough calories to maintain their thinner sizes.

It has more to do with appetite. Fat produces a hormone called leptin, which suppresses appetite. You evaluate the quantity you eat very differently depending on your appetite. A meal that makes me very full at 190 pounds will barely satiate me at 165.

If you asked 190 pounds me how many calories a meal was I'd usually give a higher number than 165 pounds me. Variation in comfortable resting weights likely has more to do with different satiation points than the number of calories burnt by an individual.

Citation? From what I've seen (for example the biggest loser study) metabolism doesn't slow down when people restrict calories. Yes - they need less after a while but that's because they weigh less. It's almost exactly what those BMR equations would predict.