Higher global diet quality score is related to lower prevalence of depression and poor quality of life among adolescent girls

BACKGROUND: Adolescence is a key time for the development of depression symptoms and the diet quality may be associated with mental health conditions. The present study examined the association between depression and quality of life (QoL) and the global diet quality score (GDQS) as a simple and standardized metric diet quality in Iranian adolescents. METHODS: This cross-sectional study was conducted on 733 adolescent girls recruited using a random cluster sampling method. A 147-item food frequency questionnaire (FFQ) was used for dietary intake assessment. The GDQS is gained by summing points of all the 25 food groups, ranged from 0 to 49. Depression symptoms were assessed using a Persian version of the Beck Depression Inventory (BDI). For assessment of health-related QoL, the Short Form 12 Survey–version 2 (SF-12v2) questionnaire was employed. Multivariable logistic regression examined the association of depression and QoL with GDQS in crude and adjusted models. RESULTS: Adolescent girls in the highest tertile of GDQS score compared with the lowest tertile had a 41% lower odds of depressive symptoms (OR: 0.59; 95% CI: 0.39–0.90, P = 0.01). The participants in the third tertile of GDQS score had lower odds of poor QoL compared with the first tertile (OR: 0.56; 95% CI: 0.37–0.85, P < 0.01). These associations remained significant (both P = 0.01) after adjustment for age, energy intake, body mass index (BMI), physical activity, and menstruation (depressive symptoms: OR: 0.59; 95% CI: 0.38–0.92; QoL: OR: 0.59; 95% CI: 0.38–0.91, P = 0.01). CONCLUSION: We found that adolescent girls with a higher score of the GDQS had lower odds of depression and poor QoL Prospective and interventional investigations are needed to reach a clear vision. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-023-05313-7.