Weight-loss surgeries among adolescents increased substantially in recent years, part of an overall rise in obesity treatments in the US.

The number of adolescents ages 10 to 19 who underwent metabolic or bariatric surgery rose about 20% in 2021 from the year before, according to a research letter published Tuesday in the Journal of the American Medical Association, Pediatrics. Rates of these surgeries, which are uncommon, also rose among minors between 2019 and 2020, even as rates for adults dipped.

The findings come as doctors take an increasingly hands-on approach to weight loss, including in young people, amid rising rates of obesity in adults and children. Medical groups like the American Academy of Pediatrics have called for expanded access to weight-loss surgery and drugs to treat youth obesity.

The practice has also attracted controversy and raised questions about whether clinicians are being overly aggressive, and whether any ages are too young for medical intervention.

Nearly 20% of US children and adolescents live with obesity, which is linked to diseases like type 2 diabetes and heart disease, according to the Centers for Disease Control and Prevention.

Metabolic and bariatric surgery alter the stomach and intestines to aid weight loss, reducing food intake and changing how the body absorbs food. Only about 1% of eligible individuals undergo surgery, in part because of barriers like cost. Of those who get weight-loss procedures, adolescents are a mere fraction of that group.

“Bariatric surgery hasn’t necessarily been accepted or embraced by the pediatric community or pediatricians,” said Sarah Messiah, an author of the paper and a professor at the University of Texas Health Science Center at Houston.

The researchers linked the increase to a 2019 American Academy of Pediatrics statement calling for greater access to weight-loss surgery and saying that evidence supports use of the procedure even in young people.

Those recommendations helped “break down some of those barriers for some pediatricians,” Messiah said. “The data at this point is overwhelming that it’s effective. It helps these adolescents lose weight. It helps them get healthier. Why should we wait?”

In January, the American Academy of Pediatrics issued a comprehensive guideline on obesity treatments for children and teenagers, including recommending weight loss drugs and evaluations for surgery in teenagers with severe obesity.

“There is no evidence that ‘watchful waiting’ or delayed treatment is appropriate for children with obesity,” said Sandra Hassink, a former president of the AAP, in a press release at the time.