Twenty-one percent of American children and teens have some form of "abnormal" blood cholesterol reading that leaves them at heightened risk for heart disease and stroke as they reach adulthood.

That's the conclusion of a review of 2011-2014 federal health data compiled by researchers at the U.S. Centers for Disease Control and Prevention.

Overall, slightly more than 13 percent of kids had unhealthily low levels of HDL ("good") cholesterol -- the kind that actually might help clear out arteries. The CDC says just over 8 percent had too-high levels of other forms of cholesterol that are bad for arteries, and more than 7 percent had unhealthily high levels of "total" cholesterol.

Obesity helped drive these trends, the CDC said. For example, more than 43 percent of children who were obese had some form of abnormal cholesterol reading, compared to less than 14 percent of normal-weight children.

Not surprisingly, rates of abnormal cholesterol readings rose as kids aged. For example, while slightly more than 6 percent of children aged 6 to 8 had high levels of bad cholesterol, that number nearly doubled -- to 12 percent -- by the time kids were 16 to 19 years of age, the CDC said.

The CDC report noted that while there were slight differences in cholesterol rates between boys and girls, race did not seem to matter.

Cardiologists weren't surprised by the findings.

"When one looks at the data it is clear that the obesity epidemic is responsible for a substantial portion of these abnormal cholesterol values," said Dr. Michael Pettei, who co-directs preventive cardiology at Cohen Children's Medical Center in New Hyde Park, N.Y. "Approximately one-third of U.S. children and adolescents are either overweight or obese.

"Clearly, the American Academy of Pediatrics' recommendations to screen all children for cholesterol status, and to take measures to prevent and manage obesity, are more appropriate than ever," he said.

Dr. Kevin Marzo, chief of cardiology at Winthrop-University Hospital in Mineola, N.Y., agreed.

"Abnormal cholesterol is a key modifiable risk factor for developing cardiovascular disease, including heart attack and stroke, in adulthood," he said. "This study confirms that preventive strategies must start in childhood, including healthy eating habits, regular exercise, and maintaining ideal body weight."

The findings were published Dec. 10 as a Data Brief from the CDC's National Center for Health Statistics.