Appetite has at least a basis in caloric need. If you don't produce as much heat, you burn fewer calories and therefore require fewer calories. Hence the differences in BMR (base metabolic rate).Bmblbzzz wrote: ↑11 Feb 2024, 4:42pm
I'm not sure about that. If you burn fewer calories maintaining bodyweight then you have more left over, from what you take in, for energy, whether that's movement or heat. But (and this brings us back closer to the main topic) I'm not at all sure that two people eating the exact same meal will get the same calories (and other nutrients) from it.
BMR calculators online always make me chuckle. An individuals BMR is indeed so individual that it's almost impossible for any kind of online test to guess.
And you're right, calorie absorption from any given meal is also individual and variable. There is a genetic component, but gut microbiome plays a big part too.