Impact of a Home-Based Obesity Prevention Intervention on Children's and Parents' BMI: Findings From the Guelph Family Health Study Randomised Controlled Trial.

BACKGROUND: To prevent the development of obesity and related comorbidities, interventions must begin early in life. This study aimed to assess the impact of a home-based obesity prevention intervention on children's and parents' body mass index (BMI). METHODS: The Guelph Family Health Study is a randomised controlled trial of a 6-month obesity prevention intervention aimed at establishing healthful household routines regarding family meals, children's screen time, physical activity and sleep among 285 families with preschool-aged children. The control group received 6 emails on child health behaviours. The analytic sample included 376 children (3.6 ± 1.3 years old, 20.2% at risk for overweight, 8.2% with overweight/obesity) and 481 parents (58.2% with overweight/obesity). RESULTS: Compared to controls, the intervention had no significant impact on children's or parents' BMI at post-intervention and 1 year after the intervention. Children in both the intervention and control groups had a non-significant decrease in BMI from baseline to post-intervention [intervention; -0.23 kg/m2 (95% CI, -0.46, 0.002); control; -0.17 kg/m2 (95% CI, -0.40, 0.06)] and from baseline to 1-year follow-up [intervention, -0.29 kg/m2 (95% CI, -0.67, 0.08); control, -0.06 kg/m2 (95% CI, -0.42, 0.30)]. CONCLUSIONS: Compared to controls, this home-based obesity prevention intervention had no significant impact on children's or parents' BMI immediately after the intervention or after 1 year of follow-up, indicating that the intervention had no additional effect compared to the control group on children's or parents' BMI over time. Future data collection phases will allow for the examination of the intervention effect on BMI as children age. TRIAL REGISTRATION: This study is registered at clinicaltrial.gov identifier: NCT02939261.