The objectives of this open trial feasibility study are to examine the impacts of intensive health behavior and lifestyle treatment (IHBLT) on youth and caregiver executive functioning (EF), weight status, health behaviors (dietary intake, disordered eating, physical activity), and psychological functioning. Investigators propose to enroll 10 youth 13 to 17 years of age who have overweight or obesity (OV/OB) and a primary caregiver. Families will receive six months of evidence-based family focused group IHBLT based on social, cognitive, and family systems theories. Families will complete assessments of EF skills (objective and self-report), weight status, dietary intake, physical activity, and psychological functioning at pre- and post-treatment.

Inclusion Criteria:

• Youth 13-17 years old
• Youth with OV/OB (BMI≥85th percentile for age/gender norms)
• Participating caregiver must be the participating youth's legal guardian
• Participating youth and caregiver speak and read English
• Participating youth and caregiver agree to attend IHBLT group meetings in-between the pre- and post-treatment assessments.

Exclusion Criteria:

• Youth pervasive developmental disorder (e.g., intellectual disability)
• Youth or caregiver in commercial weight loss program or taking prescribed medications for the prior three months that impact appetite or weight
• Youth or caregiver with documented history of eating disorder or untreated severe depression
• Both youth and caregiver scores are two standard deviations or above the mean on the CPT-3 Commissions and Stroop Interference, representing significantly higher than average EF skills.