Promoting alignment with Mediterranean and planetary health diet principles among international students: an exploratory pilot study of the MeditEat project

Introduction: The global food system is a major driving force behind environmental degradation, and dietary shifts towards more resource-efficient plant-based patterns are critical for reducing ecological pressure. The Mediterranean diet is widely recognized for its high nutritional quality and low environmental footprint, making it a relevant model for promoting sustainable eating behaviours also among mobile populations such as international students. This study evaluates dietary sustainability defined by the Planetary Health Diet Index (PHDI) among international students at baseline and the changes observed during the effect of a structured nutrition education exploratory pilot program (MeditEat).Methods: Fifteen students from diverse cultural backgrounds participated in MeditEat. The program included three in-person meetings and three online meetings, with monthly assessments based on the Mediterranean diet Pyramid and practical nutritional counseling to support the application of these concepts. Participants completed food-frequency questionnaires at baseline (T0), 3 months (T3), and 6 months (T6). Dietary data were converted into daily caloric contributions per food group using standardized procedures. The modified Planetary Health Diet Index (PHDI) was calculated, with a maximum possible score of 140. Statistical analyses, including the Shapiro–Wilk test, repeated-measures ANOVA, and Friedman test, were performed to evaluate time-related variations.Results: Total PHDI score increased significantly from baseline (75.4 ± 13.8) to T6 (82.9 ± 13.6, p = 0.01). Vegetable oil was the only individual component to show a statistically significant increase (p = 0.004), alongside non-significant descriptive trends in other components.Conclusion: Although variability across individuals remained considerable, participation in the pilot programme was associated with preliminary trends toward improved alignment with sustainable dietary patterns. The observed modest increase in PHDI score may indicate a favourable trend associated with Mediterranean diet-based nutritional education, although further research in larger, well-designed controlled studies is needed to substantiate this finding.