A new weapon in a long war: what the WHO's guidance on weight-loss drugs means for the world
On a crowded morning in Nairobi's Kibera market, vendors call across the aisles, urging passersby to try sweet, steaming samosas and mangoes gleaming like jewels. Across the world, on a quiet clinic bench in suburban Sydney, a woman opens a small pen the size of a highlighter and prepares an injection she hopes will finally stop hunger that has felt relentless for years. These two scenes -- one of abundance, one of private resolve -- are connected by an unfolding global health story.
This week the World Health Organization took a decisive step into that story. For the first time, the agency issued formal guidance endorsing the use of a new class of drugs -- GLP-1 receptor agonists, the family that includes household names like semaglutide (branded as Ozempic and Wegovy) and tirzepatide (marketed as Mounjaro) -- as tools for treating adult obesity as a chronic, relapsing condition.
The timing is wrenching: more than one billion people live with obesity worldwide, according to WHO estimates, and in 2022 roughly 3.7 million deaths were linked to conditions caused or worsened by excess weight -- more than the toll from malaria, tuberculosis and HIV combined. If current trends continue, WHO warns, the number of people living with obesity could double by 2030.
"We often talk about epidemics in terms of viruses," said Dr. Elena Vargas, an epidemiologist who has worked in community health programs across Latin America. "But obesity behaves differently: it's baked into our food systems, our workplaces, our cities. These new medicines are powerful, but they don't change the economic and social forces that pushed us here."
WHO's guidance frames GLP-1 therapies as part of long-term, person-centered care for adults, excluding pregnant women, and urges they be combined with behavioral support -- nutrition counseling, exercise programs, and social interventions -- rather than used in isolation.
"This guidance recognises obesity as a chronic disease needing comprehensive care," said a WHO statement accompanying the release. "Medication alone will not solve the crisis, but GLP-1 therapies can help millions reduce weight and the harms associated with it."
That's a measured line. Researchers are excited because clinical trials show dramatic results: many patients lose significant weight and see improvements in blood sugar, blood pressure, and cholesterol. But the long-term safety profile beyond a few years, and the best ways to combine drugs with community-level prevention, remain open questions.
In Manila, 42-year-old Maria Santos said a GLP-1 prescription gave her the first sustained relief from crushing appetite since her twenties. "For the first time in years, I could walk up the stairs without thinking about my breath or my knees," she told me in a phone call. "But the pharmacist warned me it's expensive. If I stop, I worry the weight will return."
Her fear captures a central dilemma: these drugs can be transformational, but evidence and experience suggest many people need prolonged -- or even lifelong -- treatment to sustain benefits. And prolonging access requires money, distribution systems, and political will.
Globally, the economic stakes are staggering. WHO estimates the cost of obesity to the global economy could reach $3 trillion annually by the end of this decade -- straining health systems, shrinking productivity and deepening inequalities. If GLP-1 drugs can prevent diabetes, heart attacks and cancer in some, the savings could be enormous. But who gains those savings depends on who gets the medicine.
The very popularity of GLP-1 drugs has created shortages that hurt people with type 1 and type 2 diabetes who rely on related medicines. High prices have quickly made these treatments out of reach for many countries where the burden of obesity and its complications is highest.
"We cannot let innovation deepen inequity," said Jeremy Mburu, a public health advocate working in East Africa. "If these therapies remain a luxury, middle- and low-income countries will be left behind while richer populations get healthier. That would be a moral failure."
WHO has already taken an unusual step: adding GLP-1 drugs to its Model List of Essential Medicines, a signal to governments and manufacturers that affordable versions should be prioritized. The agency urged the creation and scaling of low-cost generics to expand access in poorer nations.
Pharmaceutical pricing, patents, and intellectual property rules sit at the heart of the debate. Some countries have tools -- like voluntary licensing or compulsory licensing in public health emergencies -- that could lower costs. Others lack bargaining power to negotiate bulk prices or to invest in local production.
For all the excitement around medications, the WHO guidance returns again and again to one central idea: medication is a tool, not a cure-all. The agency calls for "intensive behavioural interventions" and population-level policies to create healthier environments -- measures that might feel mundane, but can be transformative over time.
Consider simple policy levers: taxes on sugary drinks and junk food, restrictions on advertising to children, urban planning that makes walking and cycling safe and attractive, and subsidies that make fruits and vegetables cheaper than processed snacks. In cities like Copenhagen and Bogotá, investments in bike lanes and public transit have quietly reshaped daily life. In Mexico, soda taxes have nudged consumption down. These are not silver bullets, but they change the context in which individual choices are made.
"We need a portfolio approach -- medicine for those who need it, and system change that prevents others from becoming sick in the first place," said Francesca Leone, a public-health policy researcher in Rome. "Otherwise we will be medicating around the edges of a broken system."
As readers, as patients, as taxpayers, what should we expect from our governments and pharmaceutical firms? Who should decide who gets a scarce treatment when demand outstrips supply? How do we weigh the benefits to individuals against the need to change the environments that produce poor health in the first place?
These are not academic questions. They will determine whether the coming decade bends the curve of the obesity epidemic or merely cements a two-tiered system where the wealthy access life-changing therapies and the rest shoulder the load of preventable disease.
There is reason for guarded hope. Medical innovation has changed health outcomes before -- from antiretroviral therapy for HIV to new vaccines that slashed childhood deaths. GLP-1 therapies could be another such turning point, provided societies pair them with the kind of political and economic decisions that spread benefits widely.
"Imagine a city where sugary drinks are a treat, where walking to work is safe, and where a person with obesity can get treatment without losing their house," Dr. Vargas said. "That is not utopia -- that's policy. The drugs are a lever. What we do with them will define the next generation."
So where do we go from here? The WHO's guidance is not an endpoint -- it's an invitation to reframe obesity as a chronic condition deserving sustained investment, careful regulation, and global solidarity. The question now is whether the world will answer it with the urgency, fairness and imagination the crisis demands.