In India there is a rapidly escalating epidemic of insulin resistance syndrome (diabetes and coronary heart disease). Contribution of genes and environment is under debate. Small size at birth coupled with subsequent obesity increases risk for insulin resistance syndrome in later life. The tendency of Indians to have higher body fat and central adiposity compared with other races may be programmed in utero. The adipose tissue releases not only fatty acids but also a number of proinflammatory cytokines, which increase insulin resistance and cause endothelial dysfunction. Crowding, infections, and environmental pollution in Indian cities may increase cardiovascular risk by stimulating fat cells. Prevention of diabetes and coronary heart disease in India will have to be approached throughout the life cycle.