Substantial evidence provides support for the role of diet in the prevention and control of mental disorders. However, since there is no study regarding the relationship between dietary diversity and stress or depression, we aimed to determine the relationship between the dietary diversity score (DDS) and stress and depression in women. This descriptive-analytical cross-sectional study was performed on 360 women aged 20–49 years attending health centers in the south of Tehran. The dietary intake and score of depression, anxiety, and stress were measured using a 24-h dietary recall and the 42-item depression, anxiety, stress scales questionnaire, respectively. The DDS was calculated based on the FAO 2013 guidelines. Data were analyzed using Chi-square, analysis of variance, Spearman correlation coefficient, and multivariable logistic regression tests. In total, 31.4 and 25.8% of the subjects suffered from depression and stress, respectively. After adjusting for confounders, a one-unit increase in DDS was associated with a 39% reduction in the risk of severe depression. The DDS was not significantly associated with mild or moderate depression, and no significant relationship was observed between the DDS and stress. The DDS could be inversely associated with depression in women. Since we observed no significant relationship between stress and DDS, further studies are needed in this regard.

Background: This systematic review and meta-analysis aimed to assess the effects of whey protein on serum lipoproteins and glycemic status in patients with metabolic syndrome (MetS) and related disorders. Methods: Online databases, such as Web of Science, Cochrane Library, PubMed and Scopus were systematically searched by two independent authors from inception until 30th April 2020 for English randomized clinical trials investigating the efficacy of whey protein administration in subjects with Mets or related conditions on the parameters of glycemic and lipid control compared to certain control. In order to evaluate the included studies’ methodological quality, Cochrane Collaboration risk of bias tool was applied. Using Cochrane’s Q test and I-square (I²) statistic, the included trials’ heterogeneity was also examined. Using a random-effects model, data were pooled, and weighted mean difference (WMD) was considered as the overall effect size. Results: Twenty-two studies were selected to be included in this meta-analysis. Consumption of whey protein resulted in significant reduction of HbA1c (WMD: -0.15; 95% CI: − 0.29, − 0.01) insulin (WMD: -0.94; 95% CI: − 1.68, − 0.21) and homeostasis model assessment-estimated insulin resistance (HOMA-IR) (WMD: -0.20; 95% CI: − 0.36, − 0.05). A significant reduction in triglycerides levels (WMD: -17.12; 95% CI: − 26.52, − 7.72), total cholesterol (WMD: -10.88; 95% CI -18.60, − 3.17), LDL-cholesterol levels (WMD: -8.47 95% CI: − 16.59, − 0.36) and total cholesterol/HDL-cholesterol ratio (WMD: -0.26; 95% CI: − 0.41, − 0.10) was found as well. Conclusions: This meta-analysis suggests that supplementation with whey protein had beneficial effect on several indicators of glycemic control and lipid parameters in patients with MetS and related conditions.