This article does us a great disservice by ignoring industrial sugar. The end of sugar rationing also meant that sugar could be added to industrially produced products, like bread. Visitors to America gag on the unbearable sweetness of standard sliced bread, which is commonly sweetened with high fructose corn syrup. Bread in the UK switched to the Chorleywood rapid process in the 60s, which allowed them to use low quality low protein flour. The result is a high glycemic index white bread which is rapidly digested to glucose.

That's only bread. Then consider breakfast cereals, baked products, baked beans, etc. Every staple suddenly has massive quantities of sugar.