Are calories in/out really the same for everyone?
I'm in my first year of medicine and was involved in a discussion with my peers and can't find a reliable source that refutes the fact that calories are the same for almost everyone(almost because there are rare cases of diseases) and/or that food itself has any influence on the bodies wa of converting those calories into fat mass.
More and more semi-reliable media sources are claiming that calories in/out is not the same for everyone or that the calories you take in are not the same when consumign 200kcal of salad vs 200kcal of chocolate for example.
I don't get it they all say it's more complex than that but they never mention how its more complicated, in a video I just saw the guy said it's hormonal but I'm not happy at all with that shitty "explanation" can someone who has lately made some good research on the topic shed some light? I'm starting to doubt my position.


Also: Is there a set point range on fat, are there really fatcells that we can'tn get rid of?
Shitty video source:
https://www.youtube.com/watch?v=UIju_-yZa9k