TABLE 5.

Depression severity correlates with diet, physical activity, and the KP.

	Regression model β coefficient (95% CI) n = 166	P-value
Demographic factors
Age (Years)	−0.25 (−0.80 to 0.30)	0.377
Sex	0.01 (−0.25 to 0.27)	0.929
BMI	−0.02 (−0.07 to 0.02)	0.341
Lifestyle factors
Physical activity	−0.09 (−0.16 to −0.01)	0.030
DFS (as score)	0.69 (0.32 to 1.05)	<0.001
Low Group¤ (score < 54)	Reference
Mid Group¤ (score 54–65)	0.51 (0.22–0.80)	0.001
High Group¤ (score ≥ 66)	0.56 (0.26–0.87)	<0.001
Immune marker
IL-6, fg/mL per mmol/L Cr	−0.03 (−0.06 to 0.00)	0.077
KP marker
KA, nmol/L per mmol/L Cr	−0.21 (−0.37 to−0.05)	0.009

The selected model was analysed using Mixed-effect multilevel regression to control for random effects from different studies. BMI, Body Mass Index; DFS, dietary fat and free sugar screener score; IL-6, interleukin-6; KA, kynurenic acid; Cr, creatinine. All variables except BMI were log₂-transformed prior to analysis. ¤ denotes variable was chosen to be analysed primarily as a categorical variable rather than continuous variable. Only variables with p-values < 0.05 were considered important in predicting the severity of the depressive symptoms. Significant p-value (< 0.05) are denoted in bold.