I'm also wondering if portioning isn't also at play here with ultra processed foods.

For a snack, I might eat a bag of baked potato chips (pulling this from the above quoted article) or apple slices. I think for many people, it's natural to eat the whole portion in front of you, even past the feeling of satiated (not to be confused with the feeling of being full). Like, I don't know many people who throw away a bag of chips with just 2 chips left in it. So even if the flavoring of the chips is no longer even appealing to me (I got just enough saltiness fix), I'm likely to finish the bag because it seems weird to "waste" those last 2 chips. And now, I've consumed an extra 15+ calories that I didn't even enjoy. Compare to an apple for which, even if I'm kind of sick of it but still feel compelled to eat the whole thing, may be an extra +2 calories.

Multiply over multiple snacks per week.