The purpose of this study is to investigate if a brief, motivational interviewing intervention (NOURISH+MI) can improve retention and treatment adherence for parents enrolled in an intervention for their child's overweight (NOURISH+). The investigators hypothesize that children whose parents participate in NOURISH+MI will demonstrate lower attrition and greater adherence with NOURISH+, ultimately leading to greater treatment effects, compared with children whose parents are randomized to NOURISH+ or a control group.