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.