The relationship between depression and relative fat mass (RFM): A population-based study.

Background: Relative fat mass (RFM) is a novel indicator for measuring body fat. The relationship between RFM and depression was explored using National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2018.

Methods: A general statistical description of the population included in the study was performed, and logistic analyses were used to explore the association between body mass index (BMI), waist circumference (WC), RFM and depression. Sensitivity analyses and restricted cubic spline (RCS) were also conducted to investigate the association between RFM and depression.

Results: A total of 28,836 participants were included in the study. In multivariate models, all obesity indices were associated with depression (P < 0.001). An increase of 1 SD in BMI, WC, and RFM was associated with a respective increased risk of depression of 2.3 %, 1.0 %, and 3.3 %. Excluding those taking antidepressants, the risk of depression was OR 1.88 (95 % CI: 1.26-2.79) for those with RFM in the highest quartile compared with those in the lowest quartile. After Inverse probability of weighting (IPW), the risk of depression in individuals with RFM in the highest quartile compared with individuals in the lowest quartile was 2.62 (95 % CI: 2.21-3.09). The RCS showed a possible nonlinear relationship between RFM and depression.

Conclusions: RFM is associated with depression, suggesting that attention to RFM may be helpful for depression research.