A tool for assessing changes in food preferences and health perceptions during nutritional interventions

Understanding how nutritional interventions alter food evaluations may help clarify mechanisms of dietary behavior change; however, most studies focus on intake outcomes and rarely assess within-person changes in subjective food evaluation. We developed a brief, image-based rating tool that measures two core dimensions of food evaluation, liking and perceived healthiness, using standardized food images. The tool was piloted in adults with type 2 diabetes participating in a medically supervised intervention that included structured glucose monitoring and professional dietary guidance. Ratings were collected at baseline, post-monitoring, and follow-up. In line with the methodological aim of this study, we examined whether the tool demonstrates internal coherence, sensitivity to change, and external validity against expert ratings and physiological measures, and whether it can capture item-level patterns relevant to eating behavior. Results provide preliminary evidence that the tool is feasible, it is low-burden, and capable of detecting coherent relationships between food liking and health perceptions, including coordinated within-person changes over time and meaningful associations with external benchmarks. To support scalability and self-administration, we also developed an online smartphone-based demonstration version to exemplify the task structure and user experience. Overall, this pilot study suggests that a short, flexible rating task can serve as a practical measurement tool for tracking intervention-relevant changes in food evaluation and for informing the design of future nutritional interventions.