It is possible that genetics and other factors unrelated to lifestyle protect them from chronic disease. But studies show that when people born into hunter-gatherer societies move to large cities and adopt Western lifestyles, they develop high rates of obesity and metabolic disease just like everyone else. Michael Gurven, an anthropologist at the University of California, Santa Barbara, has done extensive research on the Tsimane, a Bolivian population that lives a subsistence lifestyle of hunting, gathering, fishing and farming.