Overweight/obesity and inadequate sleep are prevalent, and frequently co-occurring, health risks among children, both of which are associated with serious medical and psychosocial health complications including risk for cardiovascular disease. Although the investigator's data suggest that disrupted or shortened sleep may be causally associated with increased energy intake and weight gain in children, and with self-regulation and neural response to food cues in adults, understanding of mechanisms involved in the sleep/eating association is incomplete, thereby impeding development of targeted, optimally timed intervention strategies. The proposed mechanistic clinical trial aims to assess the effects of an experimental sleep manipulation on eating-related self-regulation and its neural substrates, and on real-world eating behavior, among children with overweight/obesity, which will help guide research efforts towards the refinement of prevention and intervention strategies targeting sleep and its eating-related correlates to curb weight gain throughout development.