Workplace nutrition education promotes sustainable eating and Mediterranean diet adherence among university employees: a quasi-experimental pre-post study

Introduction: Workplaces are key settings for promoting healthy and sustainable dietary behaviours, yet evidence on nutrition education interventions addressing both outcomes remains limited. This study aimed to evaluate the effectiveness of a workplace nutrition education programme to improve dietary knowledge, promote sustainable food choices, and increase adherence to the Mediterranean diet among academic and non-academic university employees. Methods: A quasi-experimental pre–post intervention study was conducted among 75 academic and non-academic university employees at Universidad Isabel I. This intervention included three face-to-face nutrition education workshops lasting 30-40 min: healthy diet, food labelling, and planning your healthy menu. Posters summarising key messages were displayed after each workshop. Participants completed an online questionnaire before and after the workshop series. The questionnaire included study-specific items and items adapted from validated instruments, and collected sociodemographic data, health data, exploratory self-reported anthropometric and body weight perception data, nutritional knowledge and practices, understanding of visual plate tools, food planning, diet environmental impact, food choice, shopping habits, food-labelling use, ability to identify healthy foods, and adherence to the Mediterranean diet (range: 0–13 points). Results: The nutritional intervention significantly improved dietary knowledge (p = 0.003), with awareness of visual plate tools increasing from 72% to 100% (p < 0.001). Meal planning practices also improved (p < 0.05). Environmentally sustainable actions (e.g., buying local, seasonal produce) increased from 3.71 to 4.31 actions (p = 0.016), and Mediterranean diet adherence increased from 8.31 to 8.81 points (p = 0.034). While food-labelling consultation frequency remained unchanged, participants found it easier to identify healthy products (p = 0.002). No significant changes were observed in exploratory anthropometric or body weight perception measures. Conclusions: Workplace nutrition education effectively improved university employees' dietary knowledge and practices, promoted sustainable food choices, and enhanced adherence to the Mediterranean diet. Funding: This study received financial support from Universidad Isabel I for practical materials and informational posters.