Codesigning the Healthy Gut Diet—A Complex Dietary Behavior Change Intervention to Prevent Gestational Diabetes Mellitus

Introduction and Objective: Evidence suggests that modulating the gut microbiota during pregnancy through dietary interventions may reduce gestational diabetes mellitus (GDM) risk. To improve acceptability and reduce research waste, co-designing interventions with consumers has emerged as a powerful method of meaningful consumer engagement. This study aimed to co-design the Healthy Gut Diet, a complex dietary behavior change intervention for preventing GDM, with women who had previously experienced GDM. Methods: Co-design used a range of participatory methods with 6 researchers and 12 consumer participants across 3 online workshops. A 'behavior diagnosis' explored barriers and enablers of two dietary behaviors: increasing plant food intake and reducing ultra-processed food consumption. The COM-B model of behavior, the Theoretical Domains Framework (TDF) and the Behavior Change Wheel were used to select Behavior Change Techniques, embedded in all components of the intervention. Results: Barriers and enablers were mapped across six COM-B components and 10 TDF domains. Five intervention functions—education, enablement, environmental restructuring, persuasion, and incentivization—were employed, integrating 40 behavior change techniques. The intervention comprises telehealth dietitian sessions, participant handbooks, text messages, and social media support groups. Conclusion: The Healthy Gut Diet is the result of understanding consumer education and support preferences as well as targeting barriers to changing dietary behavior. This co-design process provided unique insights into what women want and need from dietary interventions with individualization and flexibility being perceived as key factors for success. Disclosure: N.J.L. Meloncelli: None. S. Wilkinson: None. A. Rushton: None. K. Pateman: None. S. Gallaher: None. H.M. O'Connor: None. S.J. de Jersey: None. Funding: Office of Research and Innovation, Queensland HealthThe University of Queensland, Faculty of Medicine