The World Health Organization has published its first global guideline on treating obesity in children and adolescents, and its message on the new generation of weight-loss medicines is cautious: lifestyle programs first, drugs only for teenagers, and only when structured support has not been enough.

What the guideline says

  • First-line care for all ages is a structured program combining diet, physical activity and behavior change, delivered together or as separate components.
  • Digital tools such as apps can help, when used with appropriate supervision.
  • Children aged nine and under should not be given weight-loss medication, devices or bariatric surgery.
  • Adolescents aged 10 to 19 may be considered for approved medicines, but only if a supervised, multi-component lifestyle program has not achieved the desired results.
  • Bariatric surgery remains an option only for adolescents with severe obesity.

As the WHO’s nutrition director, Luz María De Regil, put it: “The foundation of obesity care for children and adolescents is not medicine or surgery.” She added that the priority must be ensuring every child and adolescent can access quality care.

Why the guideline was needed

Obesity among people aged 5 to 19 has quadrupled since 1990, according to the WHO, affecting about 170 million children and adolescents worldwide in 2024. Obesity in childhood tends to persist into adulthood and brings earlier type 2 diabetes, high blood pressure, fatty liver disease, joint problems and, often, stigma and poorer mental health. At the same time, the arrival of highly effective GLP-1 medicines has left parents, doctors and health systems asking where drugs fit.

What is approved for teenagers

In the US, several obesity medicines are approved from age 12, including the weekly injection Wegovy (semaglutide) and the daily injection Saxenda (liraglutide). In a trial of adolescents, semaglutide combined with lifestyle counselling reduced body mass index by about 16% over 68 weeks, compared with almost no change on placebo — far more than lifestyle programs typically achieve. The newer daily pills for obesity are not approved for children.

How this compares with US guidance

The WHO’s stance is more conservative than that of the American Academy of Pediatrics, whose 2023 guideline said doctors should offer medication to adolescents aged 12 and over with obesity alongside intensive lifestyle treatment, rather than waiting for lifestyle treatment to fail, and should consider surgery referral for teenagers with severe obesity. The AAP argued that “watchful waiting” allows the disease and its complications to progress. Both bodies agree on the central role of behavioral support; they differ on timing.

Why the caution

The case for caution rests on what is not yet known. Trials in adolescents have lasted one to two years, while treatment may need to continue for much longer, and weight is typically regained when the drugs are stopped. There are open questions about effects on growth, puberty and bone development, about nutrition in young people whose appetite is suppressed, and about mental health, including the risk of triggering or masking eating disorders. A global guideline must also work for countries where these medicines are unaffordable or unavailable.

The problem with “lifestyle first”

Critics of a strict stepwise approach point out that the intensive programs shown to work — dozens of hours of family-based support over several months — are scarce, even in wealthy countries, and often have long waiting lists. Where they do exist, average weight change is modest. If the first step is not realistically available, “lifestyle first” can mean no effective treatment at all. The WHO’s emphasis on access to quality care is an acknowledgement of that gap, though the guideline cannot by itself fill it.

Obesity is not a failure of willpower

One point on which the experts agree is that childhood obesity is a chronic, complex condition shaped by genetics, biology, the food environment, sleep, family circumstances and income, not simply by choices. That is why guidelines stress involving the whole family, avoiding blame, and focusing on health and habits rather than a number on the scale.

What families can do

For parents concerned about a child’s weight, the first step is a conversation with a pediatrician, who can assess growth, check for related conditions, and advise on local programs. Useful questions include: what structured support is available, and how long is the wait? Is medication appropriate at my child’s age and stage? What monitoring would it involve, and what happens if it is stopped? Medicines for weight loss should only ever come from a prescriber and a licensed pharmacy.

The bottom line

The WHO guideline does not rule out medication for teenagers; it places it second, after supervised lifestyle treatment, and excludes it entirely for younger children. National guidelines, including in the US, give drugs an earlier role for adolescents. For an individual child, the right approach depends on age, severity, related health problems and what support is actually available. This is health news, not medical advice.