BALTIMORE -Overweight American children and adolescents have become fatter over
the last decade, according to researchers at the Johns Hopkins
Bloomberg School of Public Health and National Institute on Aging (NIA).
They examined adiposity shifts across socio-demographic groups over
time and found U.S. children and adolescents had significantly
increased adiposity measures such as body mass index (BMI), waist
circumference (WC) and triceps skinfold thickness (TST).
The increases in adiposity were more pronounced in some sex-ethnic
groups such as black girls. In addition, these groups gained more
abdominal fat over time, which was indicated by waist size and posed
greater health risks than elevated BMI. Their results are featured in
the August 2010 issue of the International Journal of Pediatric Obesity.
"Our analysis shows that the increase in adiposity among U.S.
children and adolescents was unequally distributed across
socio-demographic groups and across the spectrum of BMI, waist
circumference and triceps skinfold thickness measures," said Youfa
Wang, MD, PhD, senior author of the study and an associate professor
in the Bloomberg School's Department of International Health.
"Heavier children and adolescents gained more adiposity, especially
waist size, and these findings were most significant among children
ages 6 to 11. Ethnic disparities in mean BMI have also increased
substantially when comparing black girls with their white
counterparts for all ages combined. Solely examining the changes in
the prevalence of overweight and obesity based on fixed BMI cut
points could not gain such important insights regarding shifts in the
To examine these changes over time, researchers conducted a
comprehensive analysis of nationally representative survey data
collected from the National Health and Nutrition Examination Survey
(NHANES) since the late 1980s. They examined the changes in American
boys and girls ages 2 to 19, as well as by ethnic groups at the
"Our research suggests that U.S. young people may be at greater
obesity-related risks than what was revealed by increases in BMI, as
waist circumference is a better predictor of future health risks,
such as for type 2 diabetes and heart disease in adults," said May A.
Beydoun, PhD, staff scientist, National Institute on Aging, HIH/IRP,
and a former postdoctoral fellow in the Bloomberg School's Department
of International Health. "More vigorous efforts should be made to
understand the underlying causes. Moving forward, this could help
guide future population-based interventions including those focusing
on the total population and those targeting vulnerable or genetically
"Socio-demographic disparities in distribution shifts over time in
various adiposity measures among American children and adolescents:
What changes in prevalence rates could not reveal" was written by May
A. Beydoun and Youfa Wang.
This research was supported by the National Institute of Diabetes and
Digestive and Kidney Diseases (NIDDK) and the National Institute on