“same amount of calories”
I think this is too big of an assumption. Ultra processed foods are generally less filling and easier to digest. Eating 1000 calories of cereal or potato chips is easy. Eating 5 chicken breasts at once borderline impossible for most people. Whole foods tend to make is harder to overeat. There are exceptions ofc, like nuts, but i think the general trend holds.
You must not be american. It is literally not an option here.