Re:~ Fast food ... Saltier ... in USA ???
Not surprised, although I've not eaten much fast food outside the US (why, with the far better quality typically outside the US in non fast-food places).
I find McDonald burgers to be about the worst - I taste nothing but salt with them. I find them so salty, all I get now is their fish sandwich the few times/ year I stop there.
Haven't had chain pizza in some 20+ years, so can't say much about Pizza Hut, etc, but I do find the local pizzerias do tend to over do the salt.
Guess it's evidently formulated that way for the average american pallet - add enough salt, sugar & fat and the masses will follow. If there's not enough salt / sugar, they can always add ketchup. Then wash it all down with a 32 oz Coke to kill the after taste.