Dietary patterns and bone density among school-aged children: a cross-sectional study in China

Background Diet is an essential modifiable determinant of bone health, yet the associations between dietary patterns (DPs) and bone mineral density (BMD) in Chinese children remain limited. Objective This study aimed to investigate the relationship between overall diet and low BMD risk among school-aged children in China. Methods A total of 1,099 children aged 9-12 in China were recruited for this cross-sectional study. A semi-quantified food frequency questionnaire (FFQ) was used to assess dietary intake. A priori numerical index, the Chinese Dietary Guidelines Index for Children and Adolescents [CDGI (2021)-C] was utilized to assess dietary quality. Specific DPs were identified by using principal components analysis (PCA). The BMD of the left forearm was assessed using dual-energy X-ray absorptiometry (DXA). Spearman correlation test was conducted to investigate the associations between DPs. Multivariate logistic regression analysis and restricted cubic spline models (RCS) were applied to explore the associations between DPs and BMD. Results Three distinct DPs were identified: the plant-animal balanced pattern, the grain-tuber-meat pattern, and the bean-dairy pattern. We found a weak but significant positive correlation of the CDGI (2021)-C with the plant-animal balanced pattern (R = 0.318, P < 0.001), and with the bean-dairy pattern (R = 0.266, P < 0.001), respectively. After adjusting for covariates, adherence to the CDGI (2021)-C (Q4 vs. Q1, OR = 0.45, 95% CI: 0.27-0.75), the plant-animal balanced pattern (Q4 vs. Q1, OR = 0.50, 95% CI: 0.31-0.81), and the bean-dairy pattern (Q3 vs. Q1, OR = 0.57, 95% CI: 0.33-0.96) were associated with a lower risk of low BMD. No significant association was observed between the grain-tuber-meat pattern and low BMD (Q4 vs. Q1, OR = 1.09; 95% CI: 0.90-1.31). Conclusion Adherence to the CDGI (2021)-C and the plant-animal balanced pattern is advantageous for bone health and inversely correlated with the risk of low BMD among school-aged children in China. Additionally, moderate adherence to the bean-dairy pattern may also confer benefits to bone health. A balanced and overall healthy diet should be recommended in our daily life.