Although studies show childhood obesity rates leveling off, for certain ethnic groups they have climbed, according to a study published in the journal Pediatrics and reported by HealthDay News.

The bad news for black, Hispanic and American Indian girls is that they are two to three times more likely to have a higher body mass index (BMI) than white girls. (In fact, obesity rates for white girls decreased from a high in 2005.)

For the study, researchers from the University of California at San Francisco reviewed data on more than 8 million fifth, seventh and ninth graders who underwent school-based BMI screenings between 2001 and 2008 in that state.

Of the children studied, 46 percent were Latino, 33 percent white, almost 13 percent Asian, 8 percent black and less than 1 percent American Indian.

The data were separated into several BMI categories: overweight, obese and severely obese.

Scientists found that 38 percent of the kids were overweight, almost 20 percent were obese and 3.6 percent tipped the scales as being severely obese.

In general, researchers found that while rates of obesity for white girls peaked in 2005 then declined, the prevalence of obesity continued to increase for black and American Indian girls. Rates for Hispanic girls peaked in 2005 then leveled off, and Asian girls showed no obesity increase.

In addition, scientists found a huge racial disparity in the highest BMI group, with 4.6 percent of black girls and 4.9 percent of American Indian girls falling into this category compared with only 1.3 percent of white girls.

Overall, for their age, boys had a higher BMI index than girls. But obesity rates for white, Hispanic and Asian boys dropped within the study period, and only severely obese black boys showed an increased prevalence of obesity.

“What was encouraging was that we saw some decline in obesity, [but] we saw an increase in the racial disparities,” said Kristine Madsen, MD, lead author of the study and an assistant professor of pediatrics at the University of California at San Francisco.

What this means is that racial health disparities are key in meeting the specific challenges facing different races and cultures, said Carolyn Landis, PhD, a psychologist and associate professor of pediatrics at Rainbow Babies and Children’s Hospital in Cleveland.

It’s important to spread the message of better health and to tailor these campaigns for diverse communities, Landis added. For example, in areas where it’s unsafe for children to play outside, campaigns should include ideas for indoor activities (like dancing inside the house).

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