This is just a tiny example, but for 60 years, a small potato chip company in northern Illinois made the most amazing thick cut chips. They cooked them in vegetable shortening, (probably in lard , way back when). Anyway, apparently Illinois decided cooking retail foods in vegetable shortening was bad for us, and would no longer allow it, so the company was forced to use vegetable oil. Completely changed the character of the chips, resulting in a rather ordinary chip, instead of an outstanding one. While still better than ordinary chips, they really are nothing like they used to be.
You may confusing a small potato chip company in Northern Illinois with one in west central Illinois who made the BEST chips, Kitchen Cooked located in Busnell and Farmington, IL. The ‘health nazis’ required a change in the cooking oils used and it destroyed their original chips. Rumor has it that the old formula is back but the original customer base has been damaged by the health nazis.