Evaluating the Effectiveness of a Family-Based Lifestyle Intervention for Managing Childhood Overweight: Protocol for a Randomized Controlled Trial

Abstract

Background: Family-focused interventions promoting lifestyle behaviors such as physical activity and healthy eating can be effective strategies for obesity management in children. To maximize public health impact, there is an urgent need to develop innovative solutions to improve the scalability of childhood obesity management interventions. Stand-alone web-based interventions are easily administered but may be hindered by low participant engagement and limited support. A blended intervention that includes both facilitated web-based group sessions and self-guided resources may enhance engagement, thereby optimizing improvements in children's health outcomes. However, the long-term effectiveness of stand-alone versus blended web-based interventions to manage childhood obesity has not yet been evaluated.

Objective: The primary objective of this randomized controlled trial is to evaluate the long-term effectiveness of a blended, web-based, family-focused healthy living program (Family Healthy Living Program [FHLP]) compared to an active control (self-guided web-based educational resources) in lowering BMI z scores in children with overweight or obesity over 12 months. The secondary objective is to examine intervention effects on children's physical activity, dietary behaviors, and health-related quality of life as well as parental self-efficacy and motivation to support children's lifestyle behaviors.

Methods: This single-blind 2×4 trial aims to recruit 278 parent-child dyads across Canada to be randomly assigned to the FHLP intervention group or an active control group (1:1 ratio). The 10 weeks of FHLP activities have been designed based on the multiprocess action control framework to support children and parents in learning behavioral change skills that will enable them to improve their healthy lifestyle behaviors, and the FHLP delivery has been piloted previously. Families in the intervention group will receive weekly web-based synchronous group sessions and access to additional resources and suggested activities. Families in the control group will receive access to 10 weeks of self-guided web-based educational resources only. Outcomes, including child's height and weight, daily physical activity, dietary behaviors, health-related quality of life, and parental support, will be measured via questionnaire at 4 assessment time points over 1 year (ie, baseline, 10 wk, 6 mo, and 12 mo). Intervention engagement and attrition will also be recorded. Multiple linear regression models will be used to examine the effectiveness of the FHLP intervention compared to stand-alone web resources only.

Results: This study was funded in 2020, with 270 participants enrolled between January 2021 and May 2024. The 12-month data collection period ended in June 2025 and data analysis is currently underway. Study results are expected to be published in winter 2025. Results will be disseminated via conference presentations, peer-reviewed publications, and other media channels.

Conclusions: The blended web-based FHLP intervention has the potential to become a scalable solution for the prevention of obesity and related health conditions.

Trial registration: ClinicalTrials.gov NCT06777888; https://www.clinicaltrials.gov/study/NCT06777888.

International registered report identifier (irrid): DERR1-10.2196/76837.

Keywords: child behavior; childhood obesity; family-based intervention; health behavior change; obesity and overweight; parental support of child behavior; physical activity; web-based intervention.