14 DAY TRIAL // A new study carried out by the University of California, San Francisco, concluded that obesity rates have started declining and stabilizing for many teenagers but there are still some racial and ethnic minorities that have increasing weight problems.
Kristine Madsen, MD, MPH, an assistant professor of pediatrics at UCSF and first author of the study said that “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 [and] as our country becomes increasingly diverse, it is critical that we act quickly to address these disparities.”
The authors of the study looked at the health records of more than eight million fifth-, seventh-, and ninth-grade students in California, from 2001 through 2008, who underwent the state's mandatory school-based BMI screening.
46.4 percent were Hispanic, 32.8 percent were white, 12.6 percent were Asian, 7.7 percent were black, and 0.5 percent were American Indian adolescents.
In general, a child with a BMI at or above the 95 percentile is considered obese, and if the BMI is at or above 99 percentile, the child is severely obese.
During the seven years of observation, obesity rates at the 95 percentile decreased or stabilized for certain groups, like for white and Asian girls and boys, whose obesity rates peaked in 2005, then declined and 2008 rates reached 12 percent for white youth and 13 percent for Asians.
As for Hispanics, obesity rates were also at their most in 2005 and stabilized at 26 percent in 2008, with boys presenting a small decrease in their own; black boys kept the same rates level every year.
On the other side, the preponderance of obesity in black and American Indian girls kept climbing from 2001 to 2008, reaching respectively 22 and 23 percent, and they were more than three times as likely as white girls to be severely obese.
As for the groups at the 99th BMI percentile, only Asian youth and white boys had signs of decline after 2005, all other groups stabilizing until 2008.
Madsen said that “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.”
The researchers say that this study is very powerful as its subjects are very diverse, and even if the data was set for only one state, these results are applicable everywhere in the US, as one child in eight lives 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 added.
This is the first study that finds serious differences in obesity rates over time depending on race and ethnicity, e! Science News reports.
The research appears online in the journal Pediatrics and will be published in the September paper issue of the journal.