Researcher Robert Berkowitz of The Children's Hospital of Philadelphia analyzed data on 113 teens ages 13-17 with an average weight of 200 pounds.
Berkowitz looked at reducing their body mass indexes -- the ratio of their weight to their height -- as a way to improve their insulin sensitivity, which indicates how well their bodies handle sugar.
"Modest weight loss, an 8 percent reduction in their weight, resulted in major improvements in insulin sensitivity in these very overweight adolescents," Berkowitz said in a statement.
The study was published in the Journal of Pediatrics.
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