A newly released analysis by the U.S. Centers for Disease Control and Prevention estimates that almost one-third of Americans aged 12 to 17—about 8.4 million teenagers—had prediabetes in 2023. The figure, derived from the National Health and Nutrition Examination Survey, marks a sharp increase from a 2020 peer-reviewed estimate that put the prevalence at 18 percent. Public-health researchers say the revision reflects a change in the CDC’s methodology, details of which were not disclosed. The agency provided only a 600-word online summary and no raw data or peer-reviewed paper. "These new data highlight the magnitude of prediabetes among adolescents," a CDC spokesperson said, adding that the analysis used "the latest science and technologies." Outside experts welcomed attention to rising metabolic risk in youths but questioned the lack of transparency. Stanford nutrition scientist Christopher Gardner said he remains "skeptical of data updates" issued without full documentation. Steven Kahn, editor-in-chief of Diabetes Care, noted that without access to the underlying numbers "none of us can look at it to better understand where these numbers are derived from and what they really mean." Clinicians report more adolescents with obesity and elevated blood-sugar levels, a trend that raises the prospect of early-onset Type 2 diabetes along with future cardiovascular disease. The American Diabetes Association recommends screening overweight children as young as 10. Even if the latest CDC estimate is slightly inflated, endocrinologist Samar Hafida said, it should serve as a national "call to action" for improved diet, exercise and other preventive measures.