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 can eat a lot of weird foods, but McDonald’s food just falls into the uncanny valley for me. It’s like something an AI would synthesize from raw chemicals.