Ice cream is not heavily processed compared to the kind of protein bars that aspiring bodybuilders eat, but you can easily binge thousands of calories of ice cream in a single sitting. It's not so easy to binge protein bars, despite companies doing their chemical best to make them taste like candy.
Or compare those protein bars to the sweet, easy-to-eat bars (can't find brand names now) at Whole Foods that brag about having a small number of minimally processed ingredients. If you cram something full of honey or figs you can make it dangerously easy to feed your demons with while still being "natural" and "minimally processed." You won't see expensive bars sold to health-conscious well-off people implicated in the obesity epidemic, but that's a matter of class, not nutrition.
Why bother obsessing over abstract, ill-defined distinctions like "processed" or "ultraprocessed" instead of teaching people to recognize that companies are systematically and scientifically exploiting our human weaknesses for profit and ruining our health in the process? Educate people to look at a Snickers bar, or a bar full of honey and dried fruit from their fru-fru grocery store, and see a cold, calculated, predatory attack. Food companies attack the weaknesses in our eating behavior the way a lion seeks out the neck of a wildebeest. The lion doesn't specifically want the wildebeest to suffer and die; it just wants to eat its flesh. Likewise, Mars Inc. does not specifically want Americans to suffer from obesity and diabetes; it just wants to sell a lot of candy bars.
I suspect the obsession with these distinctions is motivated by the desire to find a positive story to address the obesity crisis with. Negative stories about food and eating are hard to sell to the public, who by and large (heh) just want to enjoy their food in an uncomplicated way. Not to mention that many people working in public health see them as a risk factor for eating disorders. Stigmatizing a category of food is a positive story because it promises us that once this subset of food is out of the picture, we can have an easy, healthy, uncomplicated relationship with food, without any need to address our own behavior. It locates the entire problem in a category of inanimate substances that can be purged from our world. It's a much happier story than saying we have desires and tendencies that don't always serve us, and that some of the most powerful forces in our society seem bent on making sure those desires and tendencies lead us to the worst possible place. But I suspect that eventually we'll have to face up to that, like we did with the tobacco industry, except that we'll have to accept the existence of the food industry and an indefinite, partly adversarial relationship with it.