Brown, Natasha A.Background: Childhood obesity is a public health problem with significant long-term implications and racial/ethnic disparities. African American extended family members play a significant role in child rearing and socialization, and research suggests that grandparents, in general, may influence children’s weight-related behaviors. There is, however, a lack of research exploring how urban African American children’s relationships with extended family members may influence children’s weight-related behaviors. Therefore, this study examines how extended family members’ roles and responsibilities may influence urban African American children’s weight-related behaviors, how extended family members socialize children to adopt weight-related behaviors, and how extended family members’ socialization practices may differ from those of primary caregivers. Methods: This study builds upon and extends the work of a previous, mixed-methods study of 31 primary caregiver-child dyads, which was designed to examine household and neighborhood factors related to childhood obesity. In Phase 2, individual semi-structured, in-depth interviews were conducted with 8 Baltimore City children; paired interviews were conducted with their primary caregivers and one adult member of each child’s extended family. Manuscript 1 combines qualitative data from both studies to present case studies of the 4 families that participated in both studies. Manuscripts 2 and 3 focus on data collected from Phase 2’s 8 family units, and present detailed analyses of familial influences on children’s physical activity and dietary behaviors, respectively. Findings: Manuscript 1 indicates that mothers and extended family members may differ in their influences on children’s weight-related behaviors, which may be related to differences in the adults’ roles and responsibilities with the children. Manuscript 2 suggests that extended family members may be more physically active with children; this may be influenced by perceived familial closeness and different relationship dynamics. Manuscript 3 indicates that children are consistently taught to value food-based family traditions; however, adults may be inconsistent in the socialization strategies used in day-to-day dietary routines. These findings suggest that future family-based obesity interventions for African American children should extend beyond the immediate family to include key extended family members and consider the extended family networks’ norms and values.HealthDisparitiesPublic HealthHealth Risk FactorsResearchobesitychildrenextended familiesAfrican Americanssocializationdietphysical activityThesis