Dietary supplement consumption is associated with lower dietary quality in Chinese university students based on a cross-sectional study

Faced with the challenges of academic pressure and independent living, university students often experience poor dietary quality and tend to consume dietary supplements as a strategy to compensate for nutritional deficiencies. This study aimed to explore the association between dietary quality and dietary supplement consumption among Chinese university students and to provide insights for strategies that support healthier dietary behaviors. A cross-sectional online survey was conducted among 459 Chinese university students aged 18 to 26 years. Dietary quality was assessed using five indicators derived from the Dietary Quality Questionnaire (DQQ): (1) the Food Group Diversity Score (FGDS), (2) the "All Five Recommended Food Groups" (ALL-5) score, (3) the Non-Communicable Disease (NCD)-Protect score, (4) the NCD-Risk score, and (5) the Global Dietary Recommendation (GDR) score. Multivariate regression models were employed to explore associations between these dietary quality indicators and dietary supplement consumption. Sociodemographic differences were analyzed using chi-square tests, independent t-tests, and Wilcoxon rank-sum tests. Subgroup analyses were additionally performed by sex and age group (18-22 vs. 23-26 years). The median scores observed were: FGDS 8 (interquartile range [IQR]: 7-9), All-5 5 (IQR: 4-5), NCD-Protect 6 (IQR: 4-7), NCD-Risk 3 (IQR: 2-5), and GDR 11 (IQR: 10-13). Lower scores on FGDS, ALL-5, and GDR were significantly associated with a higher prevalence of dietary supplement consumption, with odds ratios (ORs) of 5.67 (95% confidence interval [CI]: 2.29-14.07), 2.13 (95% CI: 1.37-3.33), and 3.96 (95% CI: 2.43-6.45), respectively. In conclusion, poorer dietary quality was associated with a higher prevalence of dietary supplement consumption among Chinese university students, but causality cannot be inferred given the study's cross-sectional design. These findings highlight the urgent need for targeted nutritional services and culturally appropriate dietary education.