The Development and Evaluation of an Intervention to Encourage Improved Engagement with UK Nutrition Labels

Nutrition labels are a policy tool that aim to encourage healthier dietary habits through changes in nutrient intake. However, consumer nutrition label engagement is inconsistent, which can lead to erroneous dietary choices. This thesis presents a series of chapters which inform the development, implementation and evaluation of a nutrition label engagement intervention for healthy UK adults.

The first empirical study investigated nutrition label engagement during a novel food choice task in 80 UK adults. It employed eye-tracking, think-aloud and individual differences measures in a single laboratory experiment. The findings supported the effectiveness of the food choice task in directing visual attention towards nutrition labels. Study 1 showed significantly reduced nutrition label engagement for purchase-based decisions and for when the nutrition labels required greater levels of interpretation. Furthermore, performance measures were lower for health related compared to nutrient-specific choices, suggesting that interventions were needed to improve consumer capability and motivations. The differences in accuracy were not predicted by known individual differences to nutrition label engagement.

The second empirical study used a mixed methods approach to explore nutrition label engagement using a refined food choice task and open-ended question survey in 111 UK adults. The quantitative findings from Study 1 were mostly replicated in a diverse, online consumer population. This demonstrated the robustness of the food choice task as an instrument to measure the effectiveness of a nutrition label engagement intervention.

Furthermore, Study 2 analysed consumer nutrition label experiences using inductive and deductive reflexive thematic analysis. The findings highlighted that accessible labels informed food choices but the complexities in nutrition information can lead to mistrust, lack of credibility and disengagement. The participants were also asked to rate BCTs and intervention approaches extracted from a systematic review to provide insights from the target audience regarding their acceptability to further inform the intervention design.

The third empirical study implemented and evaluated a novel nutrition label intervention with 140 participants, to assess its effectiveness and acceptability. There were mixed findings in relation to the intervention but some promising insights for future development were highlighted. Participants held favourable views on the intervention received which were explored using a mixed-methods approach.

The research conducted was based on strong theoretical foundations, robust measures and consumer insights into nutrition label engagement. The findings demonstrated the complexities and challenges of developing interventions at a population-level for nutrition label engagement but provided comprehensive insights to help inform future interventions.