Mexican American women are disproportionately affected by obesity and obesity-related conditions, such as type 2 diabetes. Obesity and diabetes are highly concordant in Mexican American families. Given the younger age of onset of diabetes in women with familial history, targeting mothers and their adult daughters for obesity treatment is warranted. From a family systems perspective, family-level approaches to obesity treatment can improve the adoption and maintenance of weight management behaviors. Including family members in treatment may also serve as a culturally salient intervention strategy as Mexican Americans endorse high level of familism. In contrast to traditional individual-level approaches to obesity treatment, a family-level approach grounded in familism would promote shared goals, collaborative problem solving, and communal coping when treating family members alongside each other. An important construct to consider when working with intergenerational Mexican American families is differences in acculturation, which may translate into differences in attitudes and behaviors. A wider gap in acculturation between parent and child has previously been associated with lower family functioning (e.g., poor communication, high conflict, low cohesion). However, interventions that promote bicultural competence by changing interactional patterns have been effective at improving family functioning. Hence, this study will conduct a randomized control trial testing the efficacy of a behavioral weight management intervention with brief and structured counseling on family functioning. Mexican American mothers and adult daughters (n=118 dyads) will be randomly assigned to receive standard behavioral treatment (SBT) or standard behavioral treatment plus relationship skills training (SBTR). Dyads participating in SBT or SBTR will attend 24 weekly sessions focused on nutrition and physical activity education along with behavior modification techniques. Dyads participating in SBTR will also receive experiential-based relationship skills training that draws from both general family systems concepts and behavioral family/couples therapy approaches to support familism, biculturalism, and communication competencies. The 12-month trial will consist of an intervention phase (1-6 months) and a maintenance phase (7-12 months). Assessments will be conducted at baseline and at the end of the intervention and maintenance phases. The primary outcome is weight loss. Secondary outcomes include treatment adherence (session attendance and self-monitoring records), physiological indicators of diabetes risk (hemoglobin A1c, waist circumference, and body fat percentage), health behaviors (eating and physical activity), psychological well-being (depression and perceived stress), and family functioning (subjective self-report and objective behavioral coding). Dyads in the SBTR group are expected to achieve greater improvements in primary and secondary outcomes than the STB group. Additionally, mediation by family functioning of intervention effects on primary and secondary outcomes will be examined.
