Effect of A Theory-based Multicomponent eHealth Intervention Program

This study is a two-arm pilot randomized controlled trial designed to evaluate the feasibility and preliminary effects of an Acceptance and Commitment Therapy (ACT) theory-based mobile application integrated with a smartphone pedometer plus health education on weight self-stigma and lifestyle behaviors among overweight or obese adults.

A total of 60 participants will be recruited and randomized 1:1 to the intervention (ACT-based app + pedometer + health education) or control condition. Outcomes will be assessed at baseline (T0), immediately after intervention (T1), and at 1 month after intervention (T2) and 3 months after intervention (T3) following intervention initiation. The primary outcomes are body weight (weight loss) and weight self-stigma measured; secondary outcomes include eating behavior, physical activity level, and quality of life.

Analyses will include per-protocol evaluation using linear mixed-effects models to test group, time, and group-by-time effects on primary and secondary outcomes, with intention-to-treat analyses conducted as sensitivity analyses using multiple imputation for missing weight and weight self-stigma data.

Findings will inform the design of a future definitive trial and contribute evidence on eHealth approaches to reducing weight-related stigma and supporting healthier lifestyles.