I really doubt you'll be impressed. Those foods are made for children, who have bland pallettes and like sugar. And adults who never advanced past this stage.

You can get good food in America. But it won't be a twinkie.

The store-bought junk food is pretty bad in America, to be fair. But foreigners also tend to overestimate their popularity, because American media is largely funded by product placement; The average American probably hasn’t eaten a Twinkie in months or even years.

Restaurants are where you’ll truly experience American food. You’ll be amazed at how much flavor is packed into each dish, and at how large the portions are. But the latter is largely a cultural thing; Americans typically have leftovers that they take home. Europeans will see the feast-sized portions on the table and immediately go “no wonder Americans are so fat…” In reality, Americans would expect to take half of it home.

Everybody in America seems to remember liking Twinkies as a kid but they're nasty now. Debate continues over whether the twinkies changed, or we did.

The UK food laws may be partially to blame. But American junk food has also degraded over the decades. A twinkie from the 30's-70's didn't taste the same as a modern twinkie, with some unknown portion of its sugar replaced by HFCS. But at least sugar is still the first ingredient in a twinkie. Plenty of other iconic junk food has been engineered into nonsense and just rides on the fumes of its former glory.