The glycemic index is a measure of the blood sugar response to a
fixed amount of carbohydrate from a particular food. For
example, white bread has a high glycemic index because it raises
blood sugar more than another food containing the same amount of
carbohydrate, say, lentils. Since chronically elevated blood
sugar and its natural partner, insulin resistance, are part of
the metabolic syndrome, it made sense that the glycemic index
would be a good predictor of the metabolic effect of a food. I
believed this myself for a long time. My faith in the concept
began to erode when I learned more about the diets of healthy
traditional cultures. For example, the Kitavans get 69% of their
calories from high-glycemic index carbohydrates (mostly starchy
root vegetables), with little added fat-- that's a lot of fast-
digesting carbohydrate! Overweight, elevated insulin and other
symptoms of the metabolic syndrome are essentially nonexistent.
Throughout Africa, healthy cultures make dishes from grains or
starchy tubers th