I agree with Thud, although I don't always have the discipline to just follow a plan and let things settle where they will. Sometimes, within my plan, I'll end up calorie restricting. And I'll get leaner. But when I lose weight just eating to appetite, and depending on types of food eaten/restricting carbs and pre-made foods (I actually find I'm hungrier with a fridge full of cheese and pepperoni, than full of raw meat and eggs that need cooking) etc., it stays lost. I suspect much of the problem with processed food is just that it's easy-access, low effort versus reward. Similar problem with nuts, perfectly good low carb food, just too easy to snack on.

Weight staying off when I eat to appetite, but change food types makes sense, since I just ate to appetite, and that's where my weight went. When I calorie restrict, I'll lose weight, but by definition I'm eating less than my appetite, and as I get leaner, that becomes harder, not easier, to do.