OBJECTIVES: To examine the association between weight loss behaviors and motivations for weight loss in children and adolescents and the association of weight status with these behaviors and motivations in a nationally representative sample. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) was examined, focusing on children in the United States aged 8-15 years, in repeated cross-sections from 2005 to 2011. RESULTS: Half of participants (N = 6,117) reported attempting to lose weight, and children with obesity attempted to lose weight more frequently (76%) than children who were a healthy weight (15%). Children reported attempting to lose weight by both healthy and unhealthy means: "exercising" (92%), "eating less sweets or fatty foods" (84%), "skipping meals" (35%), and "starving" (18%). The motivation to be better at sports was more likely to be associated with attempting weight loss through healthy behaviors, whereas children motivated by teasing were more likely to engage in unhealthy behaviors. Motivations for losing weight differed by weight status. CONCLUSIONS: Many children and adolescents attempt to lose weight, using either or both healthy and unhealthy behaviors, and behaviors differed based on motivations for weight loss. Future research should examine how physicians, parents, and teachers can inspire healthy behavior changes.