With all the news about Ultra Processed Foods I've always struggled to understand what makes a UPF.
Well - good thing someone at the University of São Paulo in Brazil made the Nova framework!
I think I actually understand it now. 
TLDR:
🟢 1 - Whole unprocessed foods (fruit-veg-meat-nuts)
🟡 2 - Minimally processed simple ingredients like naturally occurring spices and minerals (pepper, salt, turmeric, chili flakes)
🟠 3 - Processed foods (Literally category 1+2) Think homemade bread, rolls, cakes, cookies.
4 - Ultra Processed Foods - Industrially manufactured with ingredients that are chemically engineered for shelf stability and taste - devoid of unprocessed category 1 items or make up a very small fraction.