Household food-related consumption resources, self-reported vigorous activity, and incident depressive symptoms among middle-aged and older Chinese adults: a longitudinal CHARLS study

Physical activity is generally associated with lower depression risk, but an intensity-only questionnaire cannot distinguish the context in which activity occurs. We examined whether considering household food-related consumption alongside a self-reported vigorous-activity indicator helped characterize subsequent depressive-symptom risk. We analyzed Harmonized China Health and Retirement Longitudinal Study (CHARLS) Version D, with Wave 3 as baseline and Wave 4 as follow-up. Adults aged ≥ 45 years with baseline CES-D10 < 10 were cross-classified by vigorous activity and low per-capita household food-related consumption (lowest quartile; ≤50 yuan/person/week). Survey-weighted modified Poisson models estimated adjusted risk ratios (RRs), and marginal standardization estimated absolute risks. Weighted analyses included 4,161 participants. Compared with no vigorous activity/adequate resources, vigorous activity/low resources was associated with higher incident depressive-symptom risk (RR, 1.31; 95% CI, 1.07–1.60). Adjusted risks were 29.0% versus 22.1%, a difference of 6.82% points (95% CI, 1.33–12.31). Formal multiplicative and additive interaction estimates were compatible with the null. Results were broadly consistent across key sensitivity analyses, although some alternative definitions were less precise. Self-reported vigorous activity combined with low household food-related consumption identified a higher-risk joint profile. The findings do not indicate that vigorous activity is harmful, and formal statistical interaction with low-resource status was not supported. These results suggest that material context should be considered when interpreting questionnaire-defined vigorous activity.