Adherence to the nordic diet is associated with anxiety, stress, and depression in recovered COVID-19 patients, a case-control study

Background Follow-up of COVID-19 recovered patients to discover important adverse effects on other organs is required. The psychological health of COVID-19 patients may be affected after recovery. Aim We aimed to evaluate the association between adherence to the Nordic diet (ND) and psychological symptoms caused by COVID-19 after recovery. Method Dietary data on 246 qualified adults (123 cases and 123 controls). The dietary intake in this case-control study was calculated by a reliable and valid food frequency questionnaire (FFQ). Depression Anxiety Stress Scale (DASS), Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Short-Form Health Survey (SF-36) were used to analyze participant’s anxiety, stress, depression, sleep quality, insomnia, and quality of life of participants. Results There was a significant inverse relationship between total anxiety, stress, and depression scores and the intake of whole grains ( P < 0.05). Furthermore, there was a significant inverse association between depression and fruit intake ( P < 0.05). A significant negative correlation was found between insomnia and sleep quality and the intake of root vegetables ( P < 0.05). In the multinomial-regression model, a significant association between the Nordic diet and anxiety, stress, and depression was found only in the case group (OR = 0.719, 95% CI 0.563–0.918, p-value = 0.008; OR = 0.755, 95% CI 0.609–0.934, P-value = 0.010, and, OR = 0.759, 95% CI 0.602–0.956, P-value = 0.019 respectively). Conclusion Adherence to the Nordic diet might reduce anxiety, stress, and depression in recovered COVID-19 patients.