Sex-Specific Associations of Vegetable and Fruit Intake Categories with Depressive Symptoms Modified by Weight-Adjusted Waist Index Among Chinese Older Adults

Background: Depressive symptoms are a growing public health concern among aging populations. However, whether the association between vegetable and fruit intake and depressive symptoms varies by central adiposity and sex remains unclear. Objectives: This study aimed to examine whether vegetable and fruit intake categories are associated with depressive symptoms, and to evaluate whether the Weight-Adjusted Waist Index (WWI) and sex jointly modify these associations among older adults in Anhui Province, China. Methods: This cross-sectional study employed multistage stratified sampling across four cities in Anhui Province, China, from July to September 2019. Data on sociodemographic characteristics, WWI, weekly vegetable and fruit intake frequency, and depressive symptoms were collected from 5737 participants. Multivariable binary logistic regression models were employed to examine the associations, with analyses stratified by sex. Interaction analyses were conducted to evaluate the modifying roles of sex and WWI. Results: Among 5737 participants, the prevalence of depressive symptoms was 32.46%. After full adjustment, the V+/F− category was associated with higher odds of depressive symptoms in women (AOR = 1.25, 95% CI: 1.04–1.49). An interaction between vegetable and fruit intake categories and WWI levels was observed (pinteraction = 0.048). In stratified analyses, significant associations were observed among Q1 females with V+/F− and V−/F− categories and among Q3 males with the V−/F− category, whereas most other subgroup associations were not statistically significant after adjustment. Conclusions: The associations between vegetable and fruit intake and depressive symptoms may vary by metabolic status, as indexed by WWI, and by sex among older Chinese adults. Observed associations were more pronounced in females with low WWI and males with moderate WWI, and weaker among those with the highest WWI. These findings are exploratory and hypothesis-generating given the cross-sectional design and borderline interaction significance. Future longitudinal and intervention studies are needed to confirm these relationships and clarify the joint roles of dietary intake and central adiposity in late-life depressive symptoms.