Body Mass Index (BMI) and risk of depression in adults: A systematic review and meta-analysis of longitudinal studies

Depression rate has been correlated with Body Mass Index (BMI). However, the impact of the BMI on adult depression, which is based on longitudinal research, is unclear. The present study examined the effect of obesity and overweight on depression in adults. To do the systematic review some databases were searched such as Google Scholar, PsycInfo, Scopus and PubMed until Jun 2018. 18 studies were selected for meta-analysis after investigating the manuscripts base on eligible criteria. Meta-analysis was performed through random effects model. Also, analysis of subgroups for gender and BMI measurement was carried out and publication bias was also investigated. 18 prospective-cohort studies were included in meta-analysis. Obesity was a risk factor for depression (Pooled Risk Ratio (RR) = 1.15; and 95% confidence interval (CI) = 1.06–1.25. The pooled RR was 1.04 for the effect of overweight on the risk of depression (95% CI= CI=0.99–1.11; P = 0.135). In women, depression rate was 1.15 (95% CI = 1.05–1.26) and 1.04 (95% CI = 0.96–1.13) based on obesity and overweight respectively. In men they were 1.06 (95% CI = 0.89–1.26) and 0.96; 95% CI = 0.84–1.11 according to obesity and overweight status. Some evidence of publication bias was found after evaluating. Obesity and but no overweight seem to predict the incidence and risk of depression. Therefore, the prevention and treatment of obesity can reduce depression.