Adherence to the Mediterranean Diet in Association with Self-Perception of Dietary Behavior (Discrepancy between Self-Perceived and Actual Diet Quality): A Cross-Sectional Study among Spanish University Students of Both Genders.

: The Mediterranean diet (MD) is one of the most studied dietary patterns to date and is associated with multiple benefits for health and sustainability. However, paradoxically, adherence to the MD (AMD) has been gradually decreasing in native regions. It is necessary to identify the factors that influence AMD to reverse this trend and to mitigate the negative outcomes (for health and the environment) associated with westernized diets. The objective of this study was to assess how self-perception of dietary behavior influences AMD. : During the 28-day repeated measurement cross-sectional study, participants' dietary information was obtained from an initial form which established the self-perception of dietary behavior and the e12HR application to establish actual food consumption by individuals. Using the dietary information from both sources, the AMD index was calculated (specifically, the Mediterranean diet Serving Score (MDSS) index). Two categories of self-perception of dietary behavior were defined: Normal/underestimation: difference (MDSS index from initial form-MDSS index from e12HR application) ≤0; and Overestimation: difference >0 (with three subcategories: low (difference = 1-5), moderate (difference = 6-10), high (difference = 11-15)). : 139 (111, women; 28, men) Spanish university students were studied, with 98.6% (99.1%, women; 96.4%, men) falling into the overestimation category (they overestimated their dietary behavior); these students had significantly lower MDSS indexes, mean = 6.7, than students in the normal/underestimation category, mean = 12.0. Within the overestimation category, there were significant differences in the MDSS index: low (mean = 8.1), moderate (mean = 6.7), and high (mean = 4.9) subcategories and also differences that were significant in women but not in men. : Overestimation of dietary behavior could be associated with lower AMD in all Spanish university students and women.