The association between dietary diversity and depressive symptoms among adult population in rural Western Kenya

Abstract Low dietary diversity is a predictor of depression in high-income countries, but evidence from low-income settings where poor nutrition and depression often co-occur is scarce. We examined the association between dietary diversity and depression in rural Western Kenya. We conducted a cross-sectional analysis of data collected between June and August 2025 from 311 participants enrolled in a group-based microfinance (‘BIGPIC’) program. Depression was measured using twenty-item Centre for Epidemiologic Studies for Depression Scale, and dietary diversity was assessed based on the consumption of five food groups in the previous 24 hours using a validated scale. We used linear regression models to estimate the association between high dietary diversity and depression scores and assessed effect measure modification by wealth status. Quantile regression was used to examine variation across the distributions of depression scores. Higher dietary diversity was associated with lower depression scores (adjusted β (95 % CI): −3·49 (–6·62, −0·38)). This association was stronger among individuals with lower wealth (adjusted β (95 % CI): −6·00 (–10·46, −1·42)), compared with those with high wealth (adjusted β (95 % CI): −0·53 (–4·76, 3·68); Wald P –value for interaction = 0·0003). Effect sizes were larger at higher quantiles across 75th (Q75: β = −7·56; 95 % CI: −12·82, −2·27) and 90th (Q90: β = −6·01; 95 % CI: −12·43, 0·43) quantiles, though estimates were imprecise. These findings suggest that greater dietary diversity may be associated with improved mental health, particularly among socio-economically vulnerable individuals, and those with severe depression. Future work using longitudinal and quasi-experimental designs are needed to strengthen causal inference and clarify underlying mechanisms.