I’ve got a pretty severe sensitivity to – of all things – sugar. (I know, “sugar” isn’t very precise, but I’m pretty sure it’s either glucose, fructose, or sucrose.) I virtually never eat anything with added sugar or anything with any significant amount of natural sugar. And I’ve eaten that way for like 20 years now. I’m practically blind to half the produce department (any “sweet” fruits like apples, pears, cherries, grapes, oranges, etc) at the grocery store, let alone the candy isle.
I’ve gotten much more omnivorous as I get older, but have not eaten a fast food burger since I was a little kid. Don’t remember being bothered by them back then (unless they involved ketchup) but it’s been at least 40 years and they seem like inedible items to me now, I’d much rather have nothing.
Popeyes chicken I can still eat, and the American Chinese fast food. Oh and fries from about anywhere, though I don’t consider them nutrition, I like 'em.