Father-Inclusive Perinatal Obesity Prevention: A Randomized Clinical Trial

BACKGROUND AND OBJECTIVES Although fathers influence early child feeding, growth, and health behaviors, they are rarely included in early life obesity prevention interventions. We hypothesized that the father-inclusive First Heroes program would reduce rapid infant weight gain and improve parental weight-related and health behavior outcomes. METHODS We conducted a randomized controlled trial (2020-2023) in a Massachusetts health care system, enrolling 227 English- or Spanish-speaking mother-father dyads during the second trimester. Dyads were randomized to the First Heroes intervention—three virtual health coaching sessions plus multimedia content from pregnancy through 12 months postpartum—vs safety education control group. Primary outcomes were odds of rapid infant weight gain from birth to 6 and 12 months and infant overweight at 12 months. Secondary outcomes included maternal postpartum weight retention, paternal body mass index (BMI) change, and parent health care and infant-care behaviors. RESULTS Among 194 infants, intervention participants had lower odds of rapid infant weight gain vs control participants at 6 months (adjusted odds ratio [aOR], 0.42; 95% CI, 0.19–0.93) and 12 months (aOR, 0.49; 95% CI, 0.25–0.99); however, there was no difference in odds of infant overweight between groups. Fathers in the intervention vs control group had greater BMI reduction at 6 months postpartum (adjusted difference, −1.08; 95% CI, −2.06 to −0.11). Maternal weight outcomes were not significantly different by randomization group. CONCLUSIONS The First Heroes trial was associated with improvements in rapid infant weight gain, although other primary infant growth outcomes were not significantly different between groups. Future studies should examine strategies to sustain family-based obesity prevention across infancy.