This article focuses on the causes, consequences, and prevention of obesity among a subgroup of the American population, Black adolescent girls. Using an ecological perspective on obesity among Black adolescent girls, including feminist-womanist perspectives and historical and medical sociological perspectives, the authors discuss genetic, psychosocial, and cultural factors that may influence the propensity of Black adolescent girls' susceptibility to obesity and to diabetes, one of the major complications of obesity. Prevention strategies, including individual and structural interventions, are illuminated.