Association of caffeine and caffeine metabolites with obesity among children and adolescents: National Health and Nutrition Examination Survey (NHANES) 2009-2014.

The effect of caffeine exposure on children's health remains poorly understood. We aimed to characterize the associations of caffeine and caffeine metabolites with adiposity outcomes among children and adolescents. We performed cross-sectional analyses of 1,447 children and adolescents aged 6-19 years from the 2009-2014 National Health and Nutrition Examination Survey. The linear regression and weighted quantile sum (WQS) regression were used to explore the associations of urinary caffeine and 14 caffeine metabolites with adiposity outcomes, including body mass index (BMI) z-score, waist circumference (WC), obesity, and overweight. In linear regression models, compared with the participants who consumed low caffeine, higher BMI z-score, WC, and risks of obesity and overweight were more likely among those who consumed high caffeine (P < 0.05). In WQS regression models, an interquartile range increase in the weighted caffeine index was significantly associated with increased BMI z-score (β = 0.10, 95% CI = 0.01, 0.17) and WC (β = 1.20, 95% CI = 0.31, 2.09), and risks of obesity (OR = 1.09, 95% CI = 1.02, 1.17). Totally, no modification effect of age or gender was observed in the linear regression model. Nonetheless, in WQS models, the positive associations of caffeine exposure with WC and risks of obesity and overweight were significant in children aged 6-11 years rather than 12-19 years. When stratified by gender, caffeine exposure was significantly associated with BMI z-score and WC in both boys and girls. These results add novel evidence that caffeine exposure might be associated with adverse adiposity outcomes among children and adolescents.