Obesity rates have started to decline and level off for many adolescents, but continue to increase for certain racial and ethnic minorities, according to a new UCSF-led study. The evidence of increasing racial disparities for obesity underscores the need for more tailored intervention programs and policies that target high-risk groups, the authors conclude.
“While the decline and stabilization of obesity among certain groups is encouraging, we are seeing an increase in disparities that is troubling, especially among the most severely obese youth,” said first author Kristine Madsen, MD, MPH, an assistant professor of pediatrics at UCSF. “As our country becomes increasingly diverse, it is critical that we act quickly to address these disparities.”
Madsen and her co-authors examined trends in the prevalence of high body mass index among Hispanic, non-Hispanic white, Asian, black, and American Indian adolescents in California from 2001 through 2008. The data revealed that obesity rates at the 95th percentile declined or stabilized among a number of groups during the time period studied.
However, from 2001 through 2008, the prevalence of obesity continued to climb for black and American Indian girls, reaching 22 percent and 23 percent, respectively. Furthermore, these two groups were more than three times as likely as white girls to be severely obese, with a BMI at the 99th percentile.
When comparing groups at the 99th BMI percentile, the researchers found that only Asian youth and white boys showed any signs of decline after 2005. All other groups peaked in 2005 and then remained at a plateau through 2008. “When you look at the very heaviest end of the spectrum, the picture is pretty bleak, and we do not yet know if severe obesity rates for these groups will remain at a plateau or continue to increase,” Madsen added.
According to the researchers, the study's large and highly diverse group of subjects is a unique strength. And, although the data were confined to one state, the results show population level trends that are applicable elsewhere, since about one in eight children in the United States currently live in California.
“We need to focus on implementing real change in the places where kids spend most of their time – at home, at school and in the after-school arena – to encourage healthier habits and reduce consumption,” Madsen said. “Priorities must be reconsidered so that health is not an afterthought.”