also, metabolism and genes play a role, the latter which determines the former. people with good genes can increase metabolism to keep weight the same despite eating a lot more than needed, without becoming obese.
Biology is certainly a factor. BMR varies between individuals (even of the same weight and body composition). However it’s probably a smaller factor than the genetic influence on hunger and satiety.
And despite individual variation in BMR, I haven’t heard any evidence that some people have the ability to significantly ramp up their metabolism in response to consuming more calories.
