Nudge-Based Exercise Intervention for Adolescents With Obesity

Condition(s) studied

Investigational drug(s) / intervention(s)

Standard Exercise Intervention: Participants receive a standardized exercise program based on current clinical guidance. The program primarily consists of moderate-intensity aerobic exercise performed 3-4 times per week for 40-50 minutes per session. Participants also receive routine exercise-related health education and regular follow-up support.

Nudge-Based Exercise Intervention: Participants receive an 8-week nudge-based exercise program designed to facilitate the initiation and maintenance of physical activity. The intervention incorporates framed and visual information, social reference, default exercise options, reduced effort for accessing exercise opportunities, reminders, commitment strategies, progress feedback, and incentives. During hospitalization, participants receive structured face-to-face sessions and an exercise nudge package containing exercise equipment, activity task cards, and a reminder device. After discharge, home-based support is provided through online exercise reminders, activity recording, peer interaction, progress feedback, and incentives.

Study summary

This study will evaluate whether a nudge-based exercise program can improve body mass index (BMI) and physical activity in adolescents with obesity. About 140 adolescents aged 10-19 years will participate. Participants will be placed into one of two groups according to the order in which they are admitted to the hospital. One group will receive a standard exercise intervention, while the other group will receive an 8-week nudge-based exercise program designed to make regular physical activity easier to start and maintain.

The nudge-based program uses simple behavioral strategies to make exercise easier to start and maintain, including framed and visual information, default exercise options, reminders, peer comparison and support, goal commitment, progress feedback, and small incentives. The program combines face-to-face sessions during hospitalization with home-based support, exercise tools, activity recording, and online follow-up.

The main outcomes are changes in BMI and physical activity. Other outcomes include body composition, blood metabolic markers, health-related quality of life, and exercise self-efficacy. Assessments will be conducted before and after the intervention, with follow-up assessments used to examine whether the effects are maintained over time.

Eligibility

Primary outcome measure(s)

• Change in Body Mass Index (BMI) — Baseline and approximately 3 months after baseline
  Body weight and height will be measured at baseline and approximately 3 months after baseline. Weight in kilograms and height in meters will be combined to report a single BMI value using the formula: BMI = weight (kg) / \[height (m)\]\^2. Body weight and height are component measurements used to derive BMI for this endpoint and are not separate outcome measures. Change in BMI will be calculated as the BMI value at approximately 3 months after baseline minus the baseline BMI value. The reported unit of measure is kg/m\^2.
• Change in Physical Activity — Baseline and approximately 3 months after baseline
  Physical activity will be assessed using the Chinese version of the International Physical Activity Questionnaire-Short Form (IPAQ-SF). The questionnaire records walking, moderate-intensity, and vigorous-intensity physical activity during the previous 7 days. The activity-specific values will be converted to metabolic equivalent of task minutes per week (MET-minutes/week) and summed according to the IPAQ-SF scoring method to generate a single total physical activity score. The individual activity categories are components of the total score and are not separate outcome measures under this endpoint. Change in physical activity from baseline to the follow-up assessment will be evaluated.

Trial sites (1)

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