Why is diabetes so prevalent today?

In the Stone Age, sugar, fat, and salt were in short supply; our bodies had to store them when we came across them. To help ourselves survive, we adapted to hunger for sugars—literally, we craved them. When our ancestors were fortunate enough to find a batch of juicy berries, they couldn't afford not to eat every one in sight, since it might be weeks or months before they stumbled across the next batch.

That worked fine back when there were no grocery stores, fast-food restaurants, and pie-baking grandmothers. Now? Our energy-processing machinery is still geared to life in the Stone Age while our energy supply system is 21st Century. Because sugar (glucose) was always scarce, we developed a very efficient metabolism that could process small amounts of food and extract the maximum amount of energy. Today, diabetes is the result of a fundamental mismatch between our ancestral insides and our modern world outside.