(Bloomberg) — The obesity rate among 2- to 5-year-olds dropped by almost half in the U.S. over the past decade, according to a report that suggests a new wave of Americans may be able to avoid the heart disease and diabetes risks linked to being severely overweight.

Obesity among young children fell to 8.1 percent in 2011 to 2012, from 14 percent in 2003-2004, a the study published today in the Journal of the American Medical Association found. The results, by researchers at the Atlanta-based Centers for Disease Control and Prevention, expands on information initially reported by the federal agency in October.

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About 78 million adults are obese, or about one-third of the population, according to the CDC. While rates for teenagers and adults have largely remained the same over the last decade, according to the report, the progress seen among the very young offers hope for the future, said Risa Lavizzo-Mourey, head of the Robert Wood Johnson Foundation.

“Progress among the youngest children is especially important because we know that preventing obesity at an early age helps young people maintain a healthy weight into adulthood,” said Lavizzo-Mourey, whose nonprofit group has pledged $500 million to reduce childhood obesity in the U.S.

The CDC report used data from the National Health and Nutrition Examination Survey in drawing its conclusions. The paper’s findings didn’t give a specific reason for the change.

In August, CDC director Thomas Frieden said that a drop in obesity seen among low-income children ages 2 to 4 in 2011 might be due to policy changes in programs aimed at helping young children and mothers eat healthier, as well as an increase in breast feeding, and nutrition initiatives such as first lady Michelle Obama’s “Let’s Move” campaign.

TV screens

The CDC recommends that parents cut the amount of juice drinks their children consume and reduce children’s time in front of television and computer screens.

Obesity is measured using body mass index, or BMI, a calculation of weight and height in adults ages 20 and older. For example, a 5-foot, 4-inch woman weighing 175 pounds (80 kilograms) has a BMI of 30. A BMI of 30 or more is considered obese, while a BMI of 25 to 29.9 is considered overweight, according to the National Institutes of Health.

See also: U.S. obesity rate climbing in 2013

In children 2 to 19, obesity is determined as a BMI at or above the 95th percentile of children who are the same age and sex, the authors said. Overweight children have BMIs that are between the 85th and 95th percentile.

Cancer, osteoarthritis

Along with heart disease and diabetes, obesity can raise the risk of some cancers, osteoarthritis, sleep apnea and stroke, according to the CDC. Rates had more than doubled in children and tripled in adolescents from the early 1980s, though researchers say the numbers may now have plateaued.

A study published in January by the New England Journal of Medicine found that 5-year-olds who carry extra weight are four times as likely to become obese during their elementary school years. Almost half of those who developed obesity were overweight when school started, and of the overweight kindergartners, only 13 percent were normal weight in the eighth grade.

Older research suggests that obesity develops in the U.S. at a rate of 2.5 percent a year from adolescence to adulthood.

The drop in obesity among children ages 2 to 5 echoes decreases previously seen in some subpopulations. For instance, in August 2013, the CDC reported that obesity rates among low-income children fell in 19 U.S. states and territories in 2011. Among 2- to 4-year-olds, the declines varied from 1.8 percent to 19.1 percent, according to data from 40 states, two U.S. territories, and the District of Columbia.

“After decades of seemingly endless bad news about obesity, our collective efforts over the last several years show that we as a nation are finally moving in the right direction,” Lavizzo-Mourey said in a statement. “Of course we can’t stop now. We must redouble our efforts, and continue to focus on those children and families most at risk for obesity.”

See also: Obesity: The not-so-new “disease”

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