Fig. 1

Mediation model a for the association between depression and health related quality of life, mediated by nutrition; b for the association between nutrition and health related quality of life, mediated by depression. X: independent variable; Y: outcome variable; M: mediator variable; a: association between independent variable (X) and potential mediator (M); b: association between potential mediator (M) and outcome variable (Y), controlling for independent variable (X); c: total effect of the independent variable (X) on outcome variable (Y); c’: direct effect (unmediated) of independent variable (X) on outcome variable (Y). Model is adjusted for age, sex, ethnicity, marital status, smoking, alcohol use, educational status, perception of negligence/hatred, perceived health status compared to others