Fathers & Families study protocol

Purpose: The Fathers & Families (F&F) Study was established to address critical gaps in understanding fathers’ roles in shaping young children’s health-related behaviors and family health. F&F integrates a family systems perspective with a life course framework to examine determinants and consequences of fathers’ weight-related parenting practices. Participants: F&F is a longitudinal cohort of 1,272 fathers of children aged 1–6 years and 582 co-parents recruited between 2021 and 2023 through two phases: re-contact of male participants from the Growing Up Today Study (GUTS) and targeted recruitment through Michigan Medicine to enhance racial and ethnic diversity. Fathers complete surveys annually for up to three years (T1–T3), with parallel data collected from co-parents across many domains. A unique feature of the cohort is linkage to prospectively collected preconception data from GUTS spanning adolescence through adulthood (1996–2021). Findings to date: Results demonstrate links between boys’ diet and physical activity trajectories during adolescence and their food and physical activity parenting practices as fathers. In particular, more positive health behavior trajectories across the adolescent period (i.e., consistently healthy behaviors or improving health behaviors) were associated with more supportive food and physical activity parenting practices as fathers. Other findings include bidirectional associations between fathers’ food parenting and children’s dietary behaviors and that children’s diets were healthiest when both parents (fathers and their co-parents) use structure-based food practices. Conclusion: The F&F study addresses critical gaps in understanding fathers’ roles in shaping child health and family well-being. With multi-informant assessments of parenting, co-parenting, and child behaviors, and prospective linkage to preconception data, F&F provides a unique life-course resource to inform father-inclusive research and family-centered interventions.