Anecdotalish, but I'm not american. People I know work in the states for a period of time tend to mention they gain weight while in the states for a time, and then lose it when they get home, back to baseline, and they really can't quite put their finger on why. I figure corn syrup. It's like as subtle as the HP sauce, the stuff in England has a different recipe than the American, white vinegar, orange juice concentrate, corn syrup etc in the American one, basically cheaper ingedients, the English original has a subtler, less vinegar harsh, smokier flavour.