New federal data shows childhood and teen obesity in the United States has hit an all-time high, even as the rate of obesity among adults may be starting to level off. Two new reports published Wednesday by the Centers for Disease Control and Prevention (CDC) paint a complex picture of the nation's ongoing struggle with obesity.

The reports used measured heights and weights collected through the National Health and Nutrition Examination Survey (NHANES), a program run by the CDC's National Center for Health Statistics, to track trends over more than six decades.

The most alarming findings involve young people. The survey, conducted between August 2021 and August 2023, found that 21.1% of U.S. children and teenagers between the ages of 2 and 19 have obesity — the highest figure ever recorded. Fifty years ago, that number stood at just 5.2%.

Severe obesity among children has also surged, with 7% of kids now living with the condition, compared to just 1% roughly 50 years ago.

Dr. David Ludwig, co-director of the New Balance Foundation Obesity Prevention Center at Boston Children's Hospital and a professor of nutrition at Harvard School of Public Health, called the findings deeply troubling. "In the 1970s, children were certainly recognized [as obese] but it was the rare child, one in 20," he told ABC News. "And now we're looking at one in five children with obesity."

On the adult side, the picture is slightly more encouraging. The same 2021-2023 survey found that 40.3% of adults aged 20 and older have obesity, including 9.7% with severe obesity. While that remains an extraordinarily high number, it is down from the peak of 42.4% recorded in the 2017-2018 survey.

The CDC's findings arrive as the nation's health infrastructure faces intense scrutiny. Experts say continued monitoring, early intervention for children, and expanded access to effective treatments will be critical in determining whether these trends improve or worsen in future surveys.