For me, it has to be the UK since British food tends to be heavily processed along with a fixation on fish & chips, bangers & mash, pies and pastries with high fat content (most feature at least a fried item beside them, whether it’s an English breakfast with a hash brown) but not on the level of unhealthy to that from American cuisine.
A word can be said for the French - not in terms of how processed the food is, but a large proportion, up to 50% by some estimates, of the French population are infected with toxoplasmosis because of the amount of unpasteurised cheese and raw meat they eat
I should really visit France sometime. Sounds fantastic.
If you’re into cheeses you’re going to have a good time. The best is to travel around to locally source them, otherwise all supermarkets have a big selection but you’ll only find the most notorious cheeses this way