The Modifying Effects of Lifestyle Behaviors on the Association Between Drinking Water Micronutrients and BMI Status Among Children and Adolescents Aged 7~17: A Population-Based Regional Surveillance in 2022

This study aims to investigate the potential modifying effects of lifestyle behavior on the association between drinking water micronutrients and body mass index (BMI) in a large population of children and adolescents. Data of the present analysis came from a comprehensive regional large-scale surveillance study in 2022, involving 172,880 children and adolescents (50.71% boys vs. 49.29% girls) aged seven to seventeen. A restricted cubic spline (RCS) analysis was utilized to examine the exposure-response association of regular drinking water indices (including fluoride, nitrate nitrogen, pH, chloride, sulfates, and total dissolved solids (TDS), total hardness (TH), and chemical oxygen demand (COD)) with BMI. Generalized linear model and logistic regression were conducted to relate BMI and quartiles of drinking water micronutrients. Our findings reveal a nonlinear association between nitrate nitrogen (P for nonlinear < 0.001) and pH (P for nonlinear < 0.001) with BMI. High TH and COD levels significantly increase BMI. Notably, fluoride and chloride were associated with BMI Z-scores but not with overweight and obesity (OB). The BMI Z-score showed a more pronounced association with low and high pH levels in girls. For urban participants, increased TH levels were associated with a higher risk of OB. This study also found that adopting healthy lifestyles could mitigate the negative effects of fluoride, chloride, and sulfate on BMI Z-scores. This large surveillance study provides new insights into the complex interplay between drinking water micronutrients and BMI in children and adolescents. The association of various drinking water parameters on BMI varies, necessitating ongoing focus on their effects, particularly among girls and urban individuals. Healthy lifestyle behavior could mitigate the effects of fluoride, chloride, and sulfate on BMI Z-score.