John Hopkins BloombergIncreasing rate of obesity among adolescents and youngsters seems to be a cause for concern world over. Experts from the Johns Hopkins Bloomberg School of Public Health and National Institute on Aging (NIA) now claim that overweight American children and teens have become fatter over the last decade. Extreme levels of ethnic disparities were apparently detected.

Adiposity shifts of various socio-demographic groups were scrutinized by the authors over time. It was monitored that U.S. children and adolescents had extremely heightened adiposity measures like body mass index (BMI), waist circumference (WC) and triceps skinfold thickness (TST). The elevations in adiposity were more accurately noted in certain sex-ethnic groups like black girls. These groups supposedly gained more abdominal fat over time that was indicated by waist size and posed higher health risks than increased BMI.

“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. 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 obesity epidemic,” elucidated Youfa Wang, MD, PhD, senior author of the study and an associate professor in the Bloomberg School’s Department of International Health.

For analyzing these changes over time, investigations undertook a comprehensive analysis of nationally representative survey data. This data was gathered from the National Health and Nutrition Examination Survey (NHANES) since the late 1980s. Information regarding alterations in American boys and girls aged 2 to 19 years and changes by ethnic groups at the population level were included in the data. The experts concluded that U.S. young people are at a greater obesity-related risk than that revealed by elevations in BMI. It is assumed that waist circumference is a better predictor of future health risks, for type 2 diabetes and heart disease in adults.

Further investigations can be initiated to understand the causes of this variation. The results may aid future population-based interventions including those focusing on the total population and those targeting vulnerable or genetically susceptible groups.

The study was published in the August 2010 issue of the International Journal of Pediatric Obesity.