When Carlos Monteiro decided to operationalize UPFs by giving them a definition (laymans terms: UPF is one ingredient you wouldn't find in a traditional kitchen and wrapped in plastic) Kevin Hall from the US had the same reaction as you and decided to make a multi-million dollar experiment to disprove the definition proposed by Dr. Monteiro. Result: People who ate unprocessed lost weight, and the other group gained weight. (Groups were exchanged after 2 weeks and saw similar effects).

A link for other people who are interested in this: https://www.nih.gov/news-events/news-releases/nih-study-find...