One obvious possible explanation for the epidemics of obesity and diabetes in these Native Americans, and thus elsewhere, is that as the amount of sugar consumed per capita increases, and perhaps sugary beverages particularly, a greater proportion of the population becomes insulin-resistant. They pass over the threshold at which they can no longer tolerate the sugar they’re consuming—some of us can only tolerate a little sugar; some of us can tolerate a lot—and they manifest metabolic syndrome and then obesity and diabetes.
