Obesity simply comes from consuming more calories than you need. You can (and people have) loose weight by eating McDonalds if you wanted—you just have to make sure the amount of calories you get from it is less than what you actually need.
As the other commentator mentions, the only thing processed foods might bring, is trying to break our self-restraint by being delicious in certain ways.
This is overly simplistic. Our bodies process sugars in vastly different ways. Fructose for example was historically rare for us to have and is metabolized in basically unlimited quantity as fast as possible by the liver and transferred to fat reserves.
So yes, quantity matters but you will have incredible difficulty not putting on weight from high fructose foodstuffs because your body will tell you "eat more food" to feed your muscles well before it decides to give up any fat reserves.
Sure, but the view that it's just sugar that's bad, is even more overly simplistic, and in fact harmful. Obesity is always more deeply rooted in habits, comfort, stress and the way a person deals with things, than it is with just sugar---it's a behavioral issue that needs to be tackled at a deeper level. One calorie is one calorie, regardless of were it comes from.
You'd find very little actual scientific backing for your statement, from papers that haven't been debunked[0]. That sugar itself is bad is an age old meme that needs to die. Similarly, that kids get hyperactive with sugar is also a myth[1].
Now, your other argument that you might "feel" hungrier, is something else. You have still gotten the energy you needed, it just doesn't feel as filling, perhaps.
Your reference [0] is talking about the concept that such a thing as "sugar addiction" exists. That is not at all what I was arguing. The fructose metabolic pathway is well known, and particularly in the US, excess fructose in the diet is common due to the corn industry.
Obesity simply comes from consuming more calories than you need. You can (and people have) loose weight by eating McDonalds if you wanted—you just have to make sure the amount of calories you get from it is less than what you actually need.
As the other commentator mentions, the only thing processed foods might bring, is trying to break our self-restraint by being delicious in certain ways.