The Association Between Adherence to the Mediterranean Diet and Depression and Anxiety Symptoms in University Students: The Mediating Role of Lean Mass and the Muscle Strength Index Alfaro-González, Sofía Garrido-Miguel, Miriam Fernández Rodríguez, Rubén Mediterranean dietary pattern Physical fitness Mental health Young adults This research is a part of the “Nuts4Brain Project: The Relationship between Nut Consumption and Mental Health Outcomes Throughout Adulthood”, which is funded by the Ministry of Science and Innovation of Spain (grant number PI21/01898), supported by the Carlos III Health Institute, Spain, FEDER funds, and cofunded by the European Union’s NextGenerationEU initiative. The R.F.-R. postdoctoral contract is supported by the Spanish Ministry of Science, Innovation, and Universities, co-financed by the European Social Fund+ (JDC2023-050585-I, MCIU/AEI/10.13039/501100011033). The research group leading this study was awarded the call for the creation of health outcome-oriented cooperative research networks (RD21/0016/0025) by the Ministry of Economy and Competitiveness of Spain. The funders played no role in the study design, data collection or analysis, decision to publish, or preparation of the manuscript. Supplementary Materials: The following supporting information can be downloaded at: https://www. mdpi.com/article/10.3390/nu17020346/s1, Table S1: Descriptive characteristics by field of studies. Background/objectives: recent studies have suggested that components typical of the Mediterranean diet (MedDiet) are associated with depression and anxiety prevention. In this sense, the main objective of this study was to analyse the associations between adherence to the MedDiet and depression and anxiety symptoms and to examine whether this relationship is mediated by lean mass and the muscle strength index (MSI). Methods: a cross-sectional study (based on data obtained from the Nuts4Brain-Z study) was conducted from 2023–2024, involving 428 university students, aged 18–30 years, from a Spanish public university. Depression was assessed using the Beck Depression Inventory (BDI-II), and anxiety was assessed via the General Anxiety Disorder-7 (GAD-7) tool. Adherence to the MedDiet was assessed using the MEDAS questionnaire. Lean mass was assessed via bioimpedance, and MSI was measured via a dynamometer. ANCOVA models were used to test the mean differences in depression and anxiety scores using MEDAS categories (low adherence < 9 points vs high adherence ≥ 9 points). Serial multiple mediation models, adjusted for the main confounders, were used to explore the role of lean mass and MSI in the relationships between adherence to the MedDiet and depression and anxiety symptoms. Results: university students with high adherence to the MedDiet exhibited lower scores for depression and anxiety symptoms (p < 0.05) than did students with low adherence to the MedDiet. The mediation analysis preliminarily revealed that both lean mass and MSI acted as mediators of the relationships between adherence to the MedDiet and depression and anxiety. Conclusion:adherence to the MedDiet in university students per se does not appear to have a direct effect on depression and anxiety symptoms because these associations are partially (for depression) or entirely (for anxiety) explained by lean mass and MSI. 2025-03-03T08:13:24Z 2025-03-03T08:13:24Z 2025-01-18 journal article Alfaro-González, S.; Garrido-Miguel, M.; Pascual-Morena, C.; Pozuelo-Carrascosa, D.P.; Fernández-Rodríguez, R.; Martínez-Hortelano, J.A.; Mesas, A.E.; Martínez-Vizcaíno, V. The Association Between Adherence to the Mediterranean Diet and Depression and Anxiety Symptoms in University Students: The Mediating Role of Lean Mass and the Muscle Strength Index. Nutrients 2025, 17, 346. https://doi.org/10.3390/nu17020346 https://hdl.handle.net/10481/102805 10.3390/nu17020346 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI