Exploring the Use of Genetic and Behavioural Data in Tailoring Dietary and Lifestyle Support

Personalised nutrition approaches typically rely on static information such as health status, lifestyle and genetic data. However, adherence often remains low because daily behaviours are influenced by psychological states, motivation and real-time barriers. There is growing interest in whether integrating behavioural signals and timely prompts could strengthen engagement. The purpose of this study is to explore whether incorporating psychological adaptation and just-in-time behavioural prompts leads to better adherence to a personalised nutrition programme compared with commonly used personalised approach (combining health, lifestyle and genetics data without psycho-behavioural adaptation). Using a six-week n-of-1 randomised trial design implemented across multiple participants, the research will also assess the feasibility of delivering this adaptive support in a free-living environment, as well as participants' engagement, acceptability and perceived usefulness. Following completion of the 6-week intervention, an optional focus group will be conducted with a subset of participants (maximum 8) within four weeks of the final study day. The focus group will last approximately 60-90 minutes and will be conducted in person or via video call. Qualitative data from the focus group will be analysed using reflexive thematic analysis (Braun \& Clarke, 2021). These findings will inform the development of an adaptive personalised nutrition AI agent.