Design and development of acceptance and commitment therapy (ACT) bibliotherapy module for sustained dietary behaviour change

Abstract

The prevalence of overweight and obesity continues to rise globally, including in Malaysia. Conventional weight management strategies that focus primarily on diet and exercise often lead to short-term success but fail to sustain long-term healthy eating behaviour. This study aimed to harness human values as determinants of sustained dietary behaviour change through the Acceptance and Commitment Therapy (ACT) framework. Adopting a qualitative Design and Development Research (DDR) Type I guided by the ADDIE model, the study systematically progressed through analysis, design, and development phases. Multiple approaches were employed, including semi-structured interviews, document analysis, reflective journalling, and psychological assessment using the Acceptance and Action Questionnaire–Weight (AAQ-W). The study involved two groups, comprising a total of 14 participants: targeted users who were overweight or obese young adult females, and experts consisting of psychology academicians and registered counsellors with more than five years of ACT practice. Findings from the analysis phase informed the design and development of an ACT-based bibliotherapy prototype, which subsequently underwent formative evaluation for validity, practicality, and effectiveness. In terms of practicality, participants were able to comprehend the content of the self-help book due to the clear explanation of concepts, supported by the use of analogies and examples. The relatability of the content further helped readers to connect with and understand the underlying concepts. Six motivational themes emerged as factors that encouraged participants to complete reading the book: (1) values, goal setting, and self-monitoring; (2) relatability and personal challenges; (3) information, knowledge, and insight; (4) activities that facilitated concept mastery; (5) engaging reading experience; and (6) self-improvement and change. In terms of effectiveness, all participants demonstrated improved psychological flexibility, as evidenced by the reduction in post-intervention AAQ-W scores and reported positive changes in their eating behaviour. The final prototype, a psychoeducational self-help book titled “Making Peace with Diet,” was therefore found to be both practical and effective in enhancing psychological flexibility to promote sustained dietary behaviour change. This study contributes to the field by proposing design principles that serve as a framework for counsellors who act as instructional designers in developing ACT-based self-help interventions aimed at fostering sustainable health behaviour change within the Malaysian context. Keywords: Acceptance and Commitment Therapy, Design and Development Research, ADDIE, bibliotherapy, sustained dietary behaviour change, psychoeducational module.