The person who does the eating is the one who gets fat, yes. But if that person is eating low quality, highly processed foods with ingredients that are far more likely to cause metabolic dysfunction, then it's not just an issue of portion size (and yes, eating too much is definitely an issue too).
And I was saying for the _same_ caloric amount, regardless of density. Never mind though, pretty clear you're a troll.
The role of sugar (especially fructose) and carbohydrate intake in obesity is very important, and there's far more to it than that.
I think it'd be a lot more challenging for someone to be obese with the same caloric amount of avocados than cheetos, for example.