>Now, what UPF foods are is foods that have had most of their non-caloric content removed or been processed to increase calorie content, triggering this gorging behaviour. This is probably 80% of the obesity epidemic today.

It's been possible to buy prepared pure sugar (even granulated) and pure oils and fats for centuries, and eat them straight out of the container if one wished. Yet the obesity epidemic is much newer than that, and hardly anyone gorges themselves in that particular manner even today. There is clearly far more to it than "had most of their non-caloric content removed".