>>The factors you mention with regard to diabetes are far less simple to understand. I'm sure that people in the future will not think of us as foolish people. :)

Yeah, I got way too detailed.
It is pretty much as simple as the cigarette thing, and cigarettes=cancer took decades to become conventional wisdom.

Cigarettes = Poison the lungs = Cancer (in many but not all people)

High Carb Diet = Overworked Pancreas = Diabetes (in many but not all people)