LOS ANGELES, Feb. 9 (Xinhua) -- Pre-teen girls between the ages of nine and 12 are most likely to gain weight, a new study says.

    For this study, U.S. researchers enrolled more than 2,300 girls aged nine and 10 and followed them for at least a decade.

    Researchers measured their height, weight, blood pressure and cholesterol every year through age 18, then had the teens report their own measures at ages 21 through 23. Roughly half of the girls were white and half were black.

    The study finds that rates of overweight among the participants increased through adolescence, from 7 percent to 10 percent in the white girls and 17 percent to 24 percent in the black girls.

    Girls were 1.6 times more likely to become overweight when they were aged nine through 12 than later in adolescence, and girls who were overweight during childhood were 11 to 30 times more likely to be obese as young adults, according to the study which is published in the January issue of the Journal of Pediatrics.

    "We really need to get to kids before age nine and 10, and this really puts the pressure on elementary school, preschool and whatever societal institutions we have to really focus on young ages," said study co-author Eva Obarzanek, a research nutritionistat the U.S. National Heart, Lung, and Blood Institute.

    "This shows that obesity and other risk factors for heart disease track from younger to older. This is a wake-up call for policymakers, for schools, for parents," said Arlene Spark, associate professor of nutrition at Hunter College, in New York City.

    "The success rate for treatment is practically zero. The only thing that we can really hope for is that we can prevent children from becoming overweight and obese," he said.

    Dr. Bonita H. Franklin, a clinical assistant professor of pediatrics at New York University School of Medicine, added "Heart disease is the major cause of mortality in adults in the United States. This is implying that these factors which are known to make heart disease more likely in adults are already present in young children, so you would presume that there would be an increased health burden and probably shorter life span for this next generation."

    Being overweight, even as a child, increases the likelihood of having risk factors for cardiovascular disease, including higher blood pressure as well as elevated cholesterol, triglyceride and fasting insulin levels.

    As the health consequences of being overweight can be evident in girls as young as nine, all of which points to the need to tailor prevention efforts to ever younger ages, the study stresses.