But this begs the question for me, if you can count the calories of these ultraprocessed foods can they still contribute to a healthy lifestyle? I mean, let's consider that I eat ultraprocessed all the time, but in my calorie range, so I don't get obese; is it less healthy than for example vegan diet, or it doesn't matter that much?
That's the difficult part--the insulin spikes from ultraprocessed food will make you hungrier and eat more as well as lower your basal metabolism. "Calorie range" is a moving target.
It's not just calories, if you mostly ultraprocessed foods you're also probably lacking in vitamins, minerals, healthy fats, fiber, phytochemicals, get too much sodium, etc.