In recent years, researchers and policymakers have recognized that obesity in childhood is not simply a medical problem, but is a complex social and psychological phenomenon. Our research team used an interpersonal and intrapersonal risk model to examine the psychosocial aspects of obesity among rural children. In this article, we describe how the global study of children's obesity has broadened over the last 10–15 years, and we present our model of interpersonal and intrapersonal risk factors, which includes complex pathways with many psychosocial variables. We then describe a large prospective longitudinal study of children in Grades 1 through 4, and highlight findings from five studies guided by this model. This work illustrates opportunities for developmental scientists and practitioners to join transdisciplinary teams to develop more effective prevention and intervention programs for children.