REFRESH-daily: a short 10-item questionnaire for evaluating behavior change towards healthier and more environmentally sustainable diets

Short dietary questionnaires for measuring environmentally sustainable healthy diets in daily life are scarce. REFRESH-daily (Rapid Evaluation FoR Environmentally Sustainable Healthy diets daily) is a brief 10-item questionnaire developed to fill this gap. It is administered daily and aggregates intake data to capture weekly dietary patterns and its alignment with dietary recommendations. This study aimed to evaluate its internal consistency, relative validity, construct validity, as well as end-user acceptability. A validation study was conducted among 106 adults in Spain. Participants completed REFRESH-daily for seven days via a mobile application, alongside a 7-day digital food diary as the reference method. Internal consistency was assessed using Cronbach’s alpha. Relative validity was evaluated through multi-level Bland–Altman analyses comparing REFRESH-daily with food diary data. Construct validity was tested by examining associations between REFRESH-daily score and food consumption, nutrient intake, estimated health risks based on the Global Burden of Disease framework, and environmental impact via Life Cycle Assessment methodology. Likert-scales were used to assess acceptability. REFRESH-daily showed good internal consistency (Cronbach’s alpha = 0.71). Relative validity analyses showed a small mean difference of 0.3 points (out of 10) between REFRESH-daily and food diary scores. Higher REFRESH-daily scores were associated with greater intake of whole plant-based foods, health-promoting nutrients, lower estimated disease risks, and reduced environmental impacts. User acceptability was high. REFRESH-daily is a valid, reliable and user-friendly tool for assessing alignment with environmentally sustainable healthy diets. Its ease of use and sensitivity to subtle dietary shifts make it particularly well-suited for the integration into behavioral dietary interventions serving as a key tool for tracking progress and informing feedback in research and applied settings.