Feasibility Study of a Digital Behaviour Change Intervention (FIT-TEENS) to Increase Physical Activity Levels in Overweight and Obese Adolescents

This is the study protocol of a cluster randomised controlled trial to evaluate the feasibility of a digital behaviour change intervention (DBCI) aimed at increasing physical activity, which will be delivered via an online learning platform to Malaysian overweight and obese adolescents (aged 13-18 years). The study will be conducted in four public secondary schools in Selangor, Malaysia. Additional schools may be recruited to fulfil required sample size. Study participants will include adolescents who are either overweight or obese (BMI > 85the or >95th percentile respectively). The intervention group will receive access to a digital intervention (FIT-TEENS) over 10 weeks, which provides information on physical activity and behaviour change support towards physical activity in the local Malay language. Briefly, this DBCI is based on the Behaviour Change Wheel and Theoretical Domains Framework. FIT-TEENS contains 10 online modules, delivered via simple, interactive, user-friendly digital platform (EdApp). The modules consist of the following topics: 1) Introduction to Physical Activity 2) Physical Activity Intensity Levels 3) Benefits of Physical Activity 4) Health-Related Fitness 5) Assessing Fitness Level 6) Setting SMART Goal 7) Motivation to Change 8) Choosing the "Right" Physical Activity 9) Overcoming Barriers 10) Other healthy lifestyle aspects: Nutrition and Stress Management. No intervention will be delivered in the control group, and participants will be requested to continue their usual physical activities. However, at the end of 10 weeks, the control group participants will also receive access to the intervention. The primary outcome of this trial is the feasibility of a digital behaviour change intervention (FIT-TEENS) at increasing physical activity compared with wait-list control in overweight and obese adolescents. More specifically, the primary objectives are to determine 1) the recruitment, retention and adherence rates, including length of time required to complete participant recruitment, 2) the acceptability of the intervention and level of overall satisfaction in participants, and 3) to conduct a qualitative process evaluation with participants to explore potential mediators of behaviour change, as well as the participants' views of the intervention and trial, including barriers and facilitators to completion of the intervention. The secondary outcomes are to estimate the variability in clinical markers to inform the design of future trial, by calculating interval estimates of the mean difference over time for physical activity behaviour, self-efficacy and social support as well as body mass index (BMI) and waist circumference of participants. This will enable the statistical power calculations for future cluster-RCT to assess the effectiveness of the intervention as part of routine clinical care.