Co-designing a digital nutrition intervention for individuals with severe mental illness using the behaviour change wheel

Purpose This study aims to develop a digital nutrition intervention for individuals with severe mental illness (SMI) using a theoretically informed co-design approach. Design/methodology/approach This study will use a participatory, mixed-methods approach, incorporating public and patient involvement (PPI) to ensure user-centred intervention design. The behaviour change wheel (BCW) guides the selection of intervention functions, behaviour change techniques and delivery methods. The study will consist of three phases: (1) preparation, (2) co-design and (3) finalisation. Findings Data collection is expected to commence in March 2025. The co-design findings will directly inform the refinement of the digital nutrition intervention. Originality/value This study contributes to digital health research by outlining a structured methodology for designing a digital nutrition intervention for individuals with SMI. By integrating the BCW with PPI principles, the intervention will be theoretically robust and user-centred, addressing a gap in nutrition-focused digital interventions.