And this is why it in practice would be different: Different foods makes you feel different, and affects your willingness to be active and your ability to do hard exercise.
If you do control for activity (incredibly hard), then there's no reason why it would be different. If you don't, there are plenty of reasons why it would.
I think what you really mean is - healthier food makes you feel fuller, because it is less calorically dense
Because of that, it is easier to consume less calories when you eat healthier foods.
