The Cross-Sectional Relation of Body Mass Index to Adiposity among 8- to 19-Year-Olds within Several Races and Ethnicities

Authors

David S. Freedman, Retired from the Centers for Disease Control and Prevention, Atlanta, GA. Electronic address: DavidSFreedman@gmail.com.
Babette S. Zemel, Division of Gastroenterology, Hepatology and Nutrition, The Children's Hospital of Philadelphia, and Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.
David R. Weber, Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, PA.
William H. Dietz, Sumner M. Redstone Global Center for Prevention and Wellness, Milken Institute School of Public Health, George Washington University.

Document Type

Journal Article

Publication Date

10-22-2024

Journal

The Journal of pediatrics

DOI

10.1016/j.jpeds.2024.114375

Keywords

DXA; NHANES; adolescents; children; fat mass index; percent body fat

Abstract

OBJECTIVE: To assess the screening ability of a high body mass index (BMI) for high adiposity among 8- to 19-year-olds. STUDY DESIGN: This cross-sectional study included 6454 National Health and Nutrition Survey participants from 2011 through 2018. Fat and lean mass were measured with dual-energy X-ray absorptiometry (DXA). We expressed adiposity as fat mass index (FMI, kg ÷ m) and %fat. RESULTS: Based on the Centers for Disease Control and Prevention 95th percentile, a high BMI correctly classified a high FMI for about 95% of participants in each racial and ethnic group. About 81% (Blacks) to 90% (Hispanics) of participants with a high BMI also had a high FMI. Further, children with a high BMI were 17 (Hispanics) to 46 (Blacks) times more likely to have a high FMI than those with a "normal" BMI. The screening ability of high BMI for high %fat was weaker because levels of %fat are influenced by both fat mass (numerator) and lean mass (denominator). CONCLUSIONS: Despite differences in body composition, a high BMI is a very good screening tool for identifying high FMI not only among White 8- to 19-year-olds but also among Asians, Blacks, and Hispanics. Compared with %fat, FMI is likely a better adiposity metric among children and adolescents.

APA Citation

Freedman, David S.; Zemel, Babette S.; Weber, David R.; and Dietz, William H., "The Cross-Sectional Relation of Body Mass Index to Adiposity among 8- to 19-Year-Olds within Several Races and Ethnicities" (2024). GW Authored Works. Paper 5791.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/5791

Department

Exercise and Nutrition Sciences