Also former fat guy here. I absolutely have not had that experience. I have easily maintained being fat (or even gained) while running 15-20k a week and walking

Also former fat guy here. I absolutely have not had that experience. I have easily maintained being fat (or even gained) while running 15-20k a week and walking everywhere. It's only when I actively moderate my eating have I lost weight. Otherwise I'd just slam down Oreos or whatever. It's stupid easy to get unfilling high calorie food. It's good that it worked for you, but it clearly doesn't work for everyone.