That already exists. It's called "Shop the perimeter", skip ALL the aisles in-between.
Nabisco tried it in the mid 90’s with Snackwell products.
You do that and you can not buy spices, the majority of fruits and vegetables, rice, flour or coffee.
But you will buy a great deal of processed meats, breads, cakes and ice cream.
It is one of those slogans that sound good if you do not actually shop but is stupid in practice.
I understand all that, but what about Kellog, Post or Nabisco, one of the really big food companies.
You can shop at Whole Foods and go all natural, if 1-2 of the major food companies goes all natural for a competitive price, then ultra processed foods will be in the minority unlike today where nearly everything is ultra-processed.