Family COMIDA (Consumo de Opciones Más Ideales De Alimentos) (Eating More Ideal Food Options) - Project Summary Family COMIDA (Consumo de Opciones Más Ideales De Alimentos) (Eating More Ideal Food Options) targets the obesity epidemic in the U.S., and was developed for the Hispanic population, a community at increased risk for obesity and its associated adverse health outcomes. Hispanics, the largest U.S. ethnic minority group, reached 62.1 million in 2020 (19% of the population); the Mexican-origin population is the largest subgroup (62%). Hispanic adults are 1.2 times more likely to be obese than non-Hispanic whites (NHWs), and Hispanic children are 1.8 times more likely to be obese than NHW children. Childhood obesity is a significant predictor of obesity in adulthood. Parental obesity more than doubles the risk of future adult obesity among obese and nonobese children under age 10. This is in part due to genetics but also due to parent modeling of health behaviors, and the home environment; risk is even greater among underserved groups. In our prior work to address adult obesity in the NYC Mexican community, up to 19% met the target 5% weight loss, and in focus groups, participants were particularly concerned about obesity in their children. Participants described family as a primary motivator for behavior change, desire for group-based motivation, belief in short-term goal-setting, and time constraints as barriers to intervention adoption. In Family COMIDA, we aim to address these findings and answer the question - What is the optimal family-centered intervention (FCI) to address both adult and childhood obesity among Mexican-heritage families? FCIs, in which mutually influencing interactions within the family can support and model healthy behaviors, are considered to be the ‘gold standard’ for childhood obesity. FCIs that jointly address both adult and childhood obesity, however, are limited, and recent systematic and scoping reviews revealed a dearth of literature describing culturally tailored FCIs for Hispanics. There are gaps in understanding the optimal combination of parent- and/or child-focused intervention components, and in understanding family-level contextual factors that may impact weight related behaviors, though family functioning is known to be associated with youth obesity. To address these gaps, build upon our prior work, and answer our question of what is the optimal obesity FCI for Mexican heritage families, we are proposing Family COMIDA, the first study to use the Multiphase Optimization Strategy (MOST), an innovative methodological framework, to guide assembly of an optimized, scalable, culturally and linguistically tailored, weight loss (parents)/obesity prevention (children) FCI for Mexican-heritage families. Family COMIDA is grounded in Social Cognitive Theory (SCT) (including, e.g. goal-setting, etc.) and Family Systems Theory (FST), will address parents and children in tandem, includes group- based motivation, and utilizes mHealth to address time constraints. We will also assess family functioning as a potential mediator, and SCT constructs. We will recruit parent-child dyads (overweight/ obese parent + child aged 8-12 regardless of child’s weight) (‘parents’ includes non-parental caregivers).