For most of human history as hunters, gatherers, and agriculturalists, humans maintained an active physical lifestyle that varied with seasonal resources and promoted cardiovascular and metabolic fitness. But for the past five hundred years, since early European imperialism, there have been major changes in everyday life and, in consequence, in health. Early industrialization and globalization diffused commodities and labor-saving technologies for work and home throughout the world. In recent decades, this process has gained extraordinary momentum: With modernity, large numbers of people now live a life of low physical activity, consistent energy intake from foods, and chronic levels of psychosocial stress. These in turn result in an array of metabolic disorders, including diabetes mellitus and associated chronic conditions. In ancient Greece, diabetes as a disease was associated with the elite managerial class; by the 1970s it was characterized as a "disease of civilization," affecting mostly lower classes and ethnic minorities. Once blamed on the genetic, mental, and cultural maladaptations of indigenous peoples, ethnic minorities, and inner-city poor, it now affects the full spectrum of social classes and ethnic groups. Thirty years later, diabetes is associated with the metabolic syndrome (MetS), the co-epidemic of obesity and heart and kidney disease that is increasingly prevalent in developed and developing nations.
