WHO issues first global guidelines for childhood obesity, cautiously backs GLP-1s

The World Health Organization has released its first-ever international guidelines for managing childhood obesity, cautiously raising the profile of GLP-1 medications for some older children and teenagers.

The new guidance, released Wednesday, recommends a broad range of interventions to manage diet, boost physical activity and change behaviours for the rising number of global youth living with obesity. For some older children and teenagers, that could also mean medication or bariatric surgery.

"The foundation of obesity care for children and adolescents is not medicine or surgery, but access to comprehensive support that enables healthy eating, physical activity and sustainable behaviour change," said Dr. Luz María De Regil, the WHO's director of the department of nutrition and food safety.

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The WHO does not recommend medical treatment, surgery or weight-loss devices for children up to the age of nine. For youth from the age of 10 to 19, medical treatments may be considered only when a supervised lifestyle program hasn't achieved results, the guidance states.

London, Ont.-based pediatric endocrinologist Dr. Marina Ybarra welcomed the organization's cautious acknowledgement of medications as one avenue to tackle obesity.

"The news about WHO encouraging GLP-1 as a possible treatment for children living with obesity, I think it's very good news," she said. "Because maybe that will help us to get funding through the public system in Canada for children living with obesity. That's my biggest hope."

Roughly 170 million children and teens around the world between the ages of five to 19 were living with obesity in 2024, the WHO noted. Obesity prevalence in this age group has also quadrupled since 1990, rising from two to eight per cent.

The global recommendations echo recent Canadian guidance to manage obesity in children. That long-awaited 2025 update also called for behavioural and psychological support and, in some cases, additional medical or surgical interventions.

But Canadian physicians recommend only using GLP-1s to manage obesity in children after the age of 12, two years above the WHO's cutoff, and don't stipulate that medical intervention should only be tried after lifestyle changes.

"There is no evidence to support a stepwise approach whereby pharmacologic and surgical interventions should be offered only if behavioural and psychological interventions prove ineffective," reads the guidance published in the Canadian Medical Association Journal.

The WHO, in contrast, focused on the "practicality and universality" of diet, physical activity and behavioural changes as the pillars of obesity management.

GLP-1s and other similar medications, known by household brand names like Ozempic, Mounjaro, Rybelsus, Wegovy and Zepbound, have exploded in popularity among adults to treat obesity and diabetes.

Ybarra stressed the medications are now an effective tool for many young patients with obesity, helping to both reduce weight and improve quality of life. While some children and teens face similar side effects to older patients, including nausea, "we didn't see many of the severe complications that were seen in the adult population," Ybarra noted.

Younger and younger patients are also trying this growing class of drugs. One U.S. study revealed a 310-fold increase in GLP-1 prescriptions for children ages eight to 11 between 2019 and 2026, though overall use in this younger group remains rare.

Still, the WHO stressed the need for caution regarding GLP-1 use among children and teens, given limited research and the potential for misuse among certain groups, such as athletes or patients with eating disorders.

The WHO's new guidelines note that overall evidence linked to various medication treatments for childhood obesity, including GLP-1s, was "generally of low quality due to short term follow-up and evaluation, and [due to] the small numbers of studies and participants."

Ybarra agreed there's a lack of long-term data for the use of GLP-1s among youth, given how new these drugs are for younger patients. "The data we have though, it's very reassuring and helpful, in terms of there's more benefits than risks."

As for the line in the sand regarding children under 10 avoiding GLP-1s, María De Regil stressed in a Tuesday news conference that the agency "recommends prioritizing other interventions in this age group."

Denmark's Novo Nordisk and U.S.-based Eli Lilly are among the drug makers currently trialling pediatric obesity medications for kids as young as six, though María De Regil wouldn’t speculate on how any of those ongoing trials might change the WHO's recommendations.

Major questions still remain about how children should safely use these types of drugs, and for how long, stressed María De Regil. "We realize that this is a rapidly evolving field," she said.

With files from CBC News