It is important to determine how family variables impact health behaviors associated with weight loss in adolescents. An integrated model developed from Family Systems Theory and Social Cognitive Theory provides a framework for understanding the impact of family variables including competence, cohesion, conflict, and nurturance on adolescent health behaviors related to weight loss. This study aimed to determine the effect of a psychoeducational weight loss intervention with an additional family component on weight loss and diet in overweight adolescents (BMI ≥ 95%) enrolled in PATHS (Parents and Adolescents Toward a Healthy Start) for Health, a 16-week family-based behavioral intervention for weight management. Additionally, we determined if changes in family variables from baseline to post-intervention had an effect on study outcomes. Participants were 42 female adolescents aged 12-15 years old and their parents and were randomized to one of three treatment conditions: psychoeducational + family process (PE + FP), psychoeducational (PE), or Wait-List Control (Control). The PE + FP and PE groups received the PATHS curriculum in a group format. The PE + FP group also received a family process component targeting positive support, shared decision making, and problem-solving. Family variables are measured by the Self-Report Family Inventory and include competence, conflict, cohesion, and nurturance subscales. Outcome variables included change in BMI (Body Mass Index) z-score and energy intake (calorie intake) from baseline to post-intervention. Participants in the PE group demonstrated a significant decrease in energy intake from baseline to post-intervention compared to the PE+FP and Control group. Additionally, positive changes in nurturance from baseline to post-intervention were associated with lower levels of energy intake in adolescents. These results provide preliminary support for the PATHS intervention to reduce energy intake in adolescents; however, a family process component was not a successful addition to a psychoeducational weight loss intervention in adolescents and their parents.