Childhood obesity prevention cluster randomized trial for Hispanic families: outcomes of the healthy families study

Background: Obesity prevalence is disproportionately high among Hispanic children. Objectives: The Healthy Families Study assessed the efficacy of a culturally targeted, family-based weight gain prevention intervention for Hispanic immigrant families with children ages 5–7 years. Methods: The study used a two-group, cluster randomized trial design, assigning 136 families (clusters) to the active intervention (weight gain prevention) and 136 families to attention control (oral health). The active intervention included a 4-month intensive phase (eight classes) and an 8-month reinforcement phase (monthly mail/telephone contact). Children's body mass index z-score (BMI-Z) was the primary outcome. Results: The BMI-Z growth rate of the active intervention group did not differ from the attention control group at short-term follow-up (median 6 months; 168 families, 206 children) or long-term follow-up (median 16 months; 142 families, 169 children). Dose response analyses indicated a slower increase in BMI-Z at short term among overweight/obese children who attended more intervention classes. Moderate physical activity on weekends increased at short term. Weekend screen time decreased at short term among those attending at least one class session. Conclusion: Low class attendance likely impacted intention-to-treat results. Future interventions targeting this population should test innovative strategies to maximize intervention engagement to produce and sustain effects on weight gain prevention.