Derived Dietary Patterns and Mental Health in Apparently Healthy Iranian Adults: A Cross-Sectional Study

Background Mental health diseases rank among the most prevalent global health concerns for a large proportion of the population. This study explored the connection between meal-based dietary patterns and mental health among adults living in Iran. Methods We conducted a cross-sectional study on healthy adults in Iran, and the outcome was measured using the shortened version of the Depression, Anxiety, and Stress Scale (DASS-21). To identify the major dietary patterns, we employed Principal Component Analysis (PCA) and Latent Class Analysis (LCA). We investigated the relationship between these dietary patterns and mental health using a multivariate logistic regression. Results Anxiety, depression, and stress were identified in 54.6%, 53.9%, and 56.6% of cases in the 434 participants, respectively. Three major dietary patterns were identified based on PCA— namely “Flexitarian,” “Protein,” and “Western,” and LCA: “Picky,” “Prudent,” and “Modern Iranian” patterns. We found that the LCA-Prudent group had significantly higher scores for three dietary patterns (PCA-Flexitarian, PCA-Protein, and PCA-Western) than the other groups when we compared the PCA-derived scores across the LCA classes. In contrast, the LCA-Picky group had the lowest scores for the PCA-Protein pattern compared to the other groups. Higher adherence to the “Flexitarian” pattern was associated with 44% lower stress levels (OR: 0.56; 95% CI: 0.32-0.96; p = 0.04), while adherence to the “Western” pattern was observed to be associated with 109% higher likelihood of being stressed (OR: 2.09; 95% CI: 1.21-3.61; p = 0.02). Meanwhile, the “Protein” pattern was associated with a lower risk of anxiety (OR: 0.48; 95% CI: 0.30-0.80). In comparison to the “Picky” pattern, the “Modern Iranian” pattern, unlike the “Prudent” pattern, was associated with a 42% lower risk of anxiety (OR: 0.58; 95% CI: 0.34-0.98) in this study population. Conclusion The study employed two methods, PCA and LCA, to identify dietary patterns and highlight the potential for varying results depending on the method used. These findings suggested that dietary patterns may play a role in promoting mental health and could be useful in developing interventions for individuals with anxiety, depression, and stress. Further research is necessary to validate these associations and better understand the underlying mechanisms.