High adiposity and high body mass index-for-age in US children and adolescents overall and by race-ethnic group

• Published in: The American journal of clinical nutrition Vol. 91; no. 4; pp. 1020 - 1026
• Main Authors: Flegal, Katherine M, Ogden, Cynthia L, Yanovski, Jack A, Freedman, David S, Shepherd, John A, Graubard, Barry I, Borrud, Lori G
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 01.04.2010; American Society for Nutrition; American Society for Clinical Nutrition, Inc
• Subjects: Absorptiometry, Photon; Adiposity - ethnology; Adolescent; adolescents; Adult; age; anthropometric measurements; Biological and medical sciences; Blacks; body composition; Body fat; Body Mass Index; boys; Child; Children & youth; dual-energy X-ray absorptiometry; ethnic differences; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; gender differences; girls; Hispanic or Latino; Hispanics; Humans; Male; Mass Screening - methods; Minority & ethnic groups; Nutrition; Obesity - diagnosis; Obesity - epidemiology; Obesity - ethnology; Prevalence; Reference Values; school children; United States - epidemiology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Whites; Young Adult; United States; United States > US; Human; Body mass index; Adiposity; Adolescent; Race; Child; Age; Ethnic group
• ISSN: 0002-9165; 1938-3207
• DOI: 10.3945/ajcn.2009.28589

BACKGROUND: Body mass index (BMI)-for-age has been recommended as a screening test for excess adiposity in children and adolescents. OBJECTIVE: We quantified the performance of standard categories of BMI-for-age relative to the population prevalence of high adiposity in children and adolescents overall and by race-ethnic group in a nationally representative US population sample by using definitions of high adiposity that are consistent with expert committee recommendations. DESIGN: Percentage body fat in 8821 children and adolescents aged 8-19 y was measured by using dual-energy X-ray absorptiometry in 1999-2004 as part of a health examination survey. RESULTS: With the use of several different cutoffs for percentage fat to define high adiposity, most children with high BMI-for-age (≥95th percentile of the growth charts) had high adiposity, and few children with normal BMI-for-age (<85th percentile) had high adiposity. The prevalence of high adiposity in intermediate BMI categories varied from 45% to 15% depending on the cutoff. The prevalence of a high BMI was significantly higher in non-Hispanic black girls than in non-Hispanic white girls, but the prevalence of high adiposity was not significantly different. CONCLUSIONS: Current BMI cutoffs can identify a high prevalence of high adiposity in children with high BMI-for-age and a low prevalence of high adiposity in children with normal BMI-for-age. By these adiposity measures, less than one-half of children with intermediate BMIs-for-age (85th to <95th percentile) have high adiposity. Differences in high BMI ranges between race-ethnic groups do not necessarily indicate differences in high adiposity.