For children aged 8 to 19 years, body mass index (BMI) is strongly related to high levels of adiposity, according to a study published online June 3 in Pediatrics.
David S. Freedman, Ph.D., from the U.S. Centers for Disease Control and Prevention in Atlanta, along with colleagues, examined the cross-sectional relationship between BMI and adiposity from 2011 through 2018 among 6,923 children aged 8 to 19 years in the National Health and Nutrition Survey.
Participants underwent dual-energy X-ray absorptiometry, and adiposity was expressed as fat mass index (FMI) and percentage body fat (percentage fat).
The researchers found that 90 to 94 percent of the variability of FMI and lean mass index (LMI) were accounted for by age and BMI in each sex, although the associations with percentage fat were weaker.
The screening abilities of a BMI ≥ CDC 95th percentile for high levels of adiposity and LMI were examined, with cut points selected to ensure that the prevalence of high values for these variables would be similar to that for high BMI.
Among participants with a high BMI, 88 and 76 percent had a high FMI and high percentage fat, respectively.
Compared with those with lower BMIs, those with a high BMI were 29 times more likely to have a high FMI. The comparable relative risks were 12 for high percentage fat and 14 for high LMI.
“Our findings provide further evidence of the utility of BMI in research and clinical care,” the authors write.
