Earlier quoted context omitted.
Appetite differences are almost certainly the primary factor in why some people get heavy and others don't, but that isn't inconsistent with CICO at all.
In my opinion, the differences in appetite are caused mostly by the differences in the type of food eaten, and not by the differences between humans. In my search for a diet that would allow me to avoid gaining weight, the main successes were achieved by replacing various kinds of food that were tasty, but which did not satiate me before eating huge amounts of them, with other kinds of food that are also tasty, but w…
My sister and I grew up with the same diet. We didn't starve, but neither of us had lots of access to junk food. Yet she could be hungry once she got home and after half a plate to be already satiated.
Today she has tons of junk food in her house yet she doesn't feel the compulsion to eat more than a few bytes. I'm down to 71 kg from 83 kg back in June, but I still can't have a single cookie package in my house.