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.
The hash brown is non-traditional and basically a US-imported idea - though the style of hash brown is pretty different.
Anyway if you think we’re obsessed with processed food and frying I can only point across the North Sea to our dear cousins in Germany.