Lancet Commission Names Obesity the Largest Preventable Threat to Global Health, Ahead of Pandemics and Antimicrobial Resistance

A landmark new assessment by The Lancet Commission on 21st Century Global Threats to Health has identified obesity as the single largest preventable threat to human health for the rest of this century, estimating that decisive action on prevention and treatment could save a staggering 23.1 billion years of healthy life between now and 2100, according to the Commission’s report launched at the World Health Summit 2026 in Berlin this week.

The figure places obesity’s avoidable toll well ahead of the other major challenges of our time — including future pandemics, antimicrobial resistance and climate change — in the most comprehensive effort yet to measure where policy action could make the greatest difference to human survival and well-being over the coming 75 years.

The Commission, co-chaired by Professor Christopher JL Murray, Director of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, and Dr Natalia Kanem, former Executive Director of the United Nations Population Fund, brought together 35 leaders spanning health, economics, security, governance and technology. Drawing on historical evidence and new risk analysis covering 204 countries and territories, the authors examined hundreds of possible threats and narrowed them to 17 that pose the greatest danger to human health and survival from 2025 to 2100 — and on which governments, funders and industry have what the authors call “a realistic route to act” through policy change, funding decisions and innovation.

How the threats were measured

Rather than ranking threats by their worst imaginable outcome, the Commission measured each one by the gap between a plausible best-case future and a plausible worst-case future — the number of disability-adjusted life years (DALYs), or years of healthy life lost to illness, disability or premature death, that targeted action could avoid. A threat was classified as “catastrophic” only if it could account for at least one billion DALYs by 2100, if there were sufficient data to model it, and if there was enough scope for policy action to matter.

On that measure, obesity stands alone at the top. The Commission estimates that policies to reduce obesity risk — driven by high body mass index, poor diet and physical inactivity — could avert 23.1 billion DALYs by the end of the century. Obesity is described as a significant and growing burden that is forecast to compound over time, feeding into diabetes, cardiovascular disease, several cancers and a host of other conditions that together erode both length and quality of life.

“The estimates highlight how much health loss could be avoided in each area,” Professor Murray said. “Some are already imposing substantial health burdens today, while others carry a real danger if they materialize. Crucially, all 17 threats are interconnected, which is why they must be addressed together, not in isolation.”

The 17 threats — and the surprising order

The full list of catastrophic threats, in alphabetical order, runs from air pollution, antimicrobial resistance, childhood malnutrition and climate change through conventional conflict, declining development assistance for health, high alcohol use, high blood pressure, income inequality, low educational attainment, malicious use of artificial intelligence, naturally occurring pandemics, nuclear conflict, obesity, poor mental health, smoking and unhealthy ageing.

When measured by avoidable healthy life lost, the five largest were: obesity at 23.1 billion DALYs; low educational attainment at 16.1 billion; income inequality at 13.8 billion — a burden the Commission says is equivalent to 25 COVID-19 pandemics; malicious use of AI at 10.4 billion; and nuclear conflict and poor mental health tied at 9.35 billion DALYs each.

Two threats were identified as having extinction potential: the malicious use of artificial intelligence and nuclear conflict. The Commission stresses that the likelihood of both remains low, but their consequences are so profound that they belong in the top tier. Action to prevent nuclear conflict, it estimates, could avert 133 million deaths and 9.35 billion DALYs by 2100.

Climate change, while classed as a threat to “human survival” itself, produced one of the smaller headline numbers: limiting warming to around 1.8°C rather than letting it reach 4.4°C could prevent 1.89 billion years of healthy life being lost to extreme heat and air pollution. The authors caution that this figure captures only direct, measurable harms today and excludes displacement, drought, economic disruption and mental-health impacts — meaning the true burden is likely greater, and will compound other threats in ways the model cannot yet reflect.

Education, inequality and Africa’s burden

Some of the starkest findings concern not diseases but social conditions. Low educational attainment accounts for 16.1 billion avoidable DALYs, with women and children in sub-Saharan Africa facing the greatest potential burden. Faster progress on education, the Commission argues, would substantially improve health outcomes, reduce mortality among children of educated mothers, and indirectly slow population growth over the long term.

Income inequality could impose an amenable health burden equivalent to 25 COVID-19 pandemics by 2100 — a striking comparison that reframes inequality not as a background condition of economic policy but as a direct engine of illness and early death. Sub-Saharan Africa is also forecast to bear around 70 per cent of the amenable health burden linked to a collapse in development assistance for health, underscoring how dependent the world’s most vulnerable health systems remain on aid flows that are now under pressure in many donor countries.

“Recent global events show us just how quickly stability can give way to crisis, and how costly it is to respond only after disaster strikes,” said Dr Kanem. “And the global threats to health risk amplifying existing inequalities, with the greatest burden falling on the most vulnerable communities. Yet the future is not inevitable.”

A three-part global call to action

The Commission sets out a clear agenda for leaders across health, finance, defence, climate and security. First, build readiness: create and fund threat-ready health systems with dedicated teams for foresight, prevention, preparedness and protection, financed durably rather than through ad hoc crisis responses, and designed to reach lower-resource settings and marginalised communities, not only wealthier populations.

Second, back breakthroughs: increase investment in innovation where existing tools fall short — including new vaccines, new antibiotics, new obesity treatments and climate technologies — alongside appropriate governance and equitable access, so that innovations reach the people who need them rather than only those who can pay.

Third, track threats: reassess risks regularly and independently so that evidence keeps pace with emerging dangers and reaches decision-makers in finance and security as well as health — including through a new institutional mechanism, the Lancet Monitor of 21st Century Global Threats to Health.

The Commission emphasises that proven and emerging solutions for most of these threats already exist and are ready to be scaled up, from medicines and health technologies to proven public policies — while a smaller number require targeted investment to reach their full potential.

“A radical conceptual shift”

Dr Richard Horton, editor-in-chief of The Lancet, described the report as offering “a radical conceptual shift in the way we think about future threats to human survival,” arguing that the jeopardies facing humanity are multiple and interconnected — and that solutions must match that reality. An accompanying Lancet editorial sounded one important note of caution: the Commission does not present a fixed ranking of threats or policy priorities. Its analysis should be seen as a dynamic process whose findings will change as new evidence arrives, and threats with smaller estimated burdens may still demand urgent action because of their potential consequences.

That caveat matters for how the headline numbers are read. The amenable-DALY measure rewards threats where the gap between good and bad futures is widest — in other words, where policy has the most room to move. It is a measure of agency, not of doom.

Analysis: Why It Matters

Obesity at the top is a provocation — and that is the point

That obesity should outrank pandemics, antimicrobial resistance and climate change on any league table of threats to human survival will surprise many readers. The instinct is to rank existential danger by catastrophe: a pandemic that kills millions in a year, a nuclear exchange, a runaway climate tipping point. But the Commission has deliberately chosen a different yardstick — avoidable suffering — and that choice changes the answer. Obesity does not threaten humanity in a single dramatic act; it grinds it down, person by person, decade by decade, through heart disease, stroke, diabetes and cancer. The 23.1 billion DALY figure is the arithmetic of that grind made visible across 204 countries and 75 years. The surprise is not a statistical quirk; it is the Commission’s central argument in miniature. The threats that end the most healthy life are not the ones that make the most dramatic television.

The number measures policy space, not inevitability

Perhaps the most important thing to understand about the headline figure is what it does not claim. The 23.1 billion DALYs are not a forecast of what will happen; they are the distance between two plausible futures — one in which prevention, treatment and equitable access improve, and one in which they do not. That makes the number a measure of leverage. A threat sits at the top of this ranking precisely because something can be done about it: taxes on sugary drinks, urban planning that makes movement easy, food environments that do not push calories at every turn, and the new generation of obesity medicines — the Commission explicitly names new obesity treatments among the innovations worth backing — all widen the gap between the two futures. The Lancet editorial’s caveat is the key to reading the whole report: threats with smaller numbers may still be more urgent, and these estimates will shift as evidence accumulates. This is a decision-maker’s map of where action buys the most health, not a doom index.

Social determinants beat pathogens — a redefinition of survival

Look again at the top three: obesity, low educational attainment, income inequality. Two of the three are not medical conditions at all. The Commission is saying, in the language of epidemiology, what public-health researchers have argued for decades: that the conditions in which people are born, learn, work and eat determine survival at least as powerfully as any virus or bacterium. The equivalence of income inequality to 25 COVID-19 pandemics is the kind of framing designed to cross the wall between health ministries and finance ministries — the people who actually decide tax policy, labour policy and education budgets. If this report has an audience beyond health, it is in those rooms, and the DALY metric is the common currency meant to get the Commission invited in.

The medicine-versus-policy tension is the real fault line

The timing of this report intersects with one of the most contested developments in medicine: the arrival of powerful new weight-loss medicines. The Commission’s call to invest in “new obesity treatments” alongside proven public policies hints at a debate that will only intensify. Are these drugs a historic chance to shrink the obesity burden at population scale — or an expensive, lifelong medicalisation of a problem whose cheapest solutions are policy ones: food pricing, advertising rules, active cities? The history of public health suggests the answer will not be either/or but both, sequenced badly: rich countries will buy their way out with drugs first, while the food environments that created the problem keep operating untouched. The Commission’s insistence on equitable access is a warning against exactly that outcome. Without it, the 23.1 billion avoidable DALYs risk becoming a benefit captured by the wealthiest health systems — which would widen, not narrow, the inequalities the report identifies as threats in their own right.

Berlin as the launchpad matters

Launching at the World Health Summit in Berlin — under the theme “From Crisis to Resilience” — was no accident. The Summit’s own announcements this week touched on many of the Commission’s 17 threats directly: antimicrobial resistance, pandemic preparedness, health systems in conflict settings, and trust in science, which new Wellcome data shows has fallen since the COVID-19 pandemic. A report that says “humanity still has the agency to act” lands differently at a gathering of the people expected to do the acting. The question now is whether it survives the flight home — whether any finance ministry, defence department or education department changes a budget line because a health commission assigned it a share of 23.1 billion lost years. That is the test Professor Murray set: delays, he said, only “shift and increase the costs into the future.” The report is published. The meter is now running.

What to Watch Next

1. The Lancet Monitor: The Commission proposes a permanent Lancet Monitor of 21st Century Global Threats to Health to track these risks independently and regularly. Watch whether it launches with funding and a publication schedule — or joins the long list of proposed dashboards that never materialise.
2. National obesity strategies: Which governments respond with concrete policy — sugary-drink taxes, advertising restrictions, urban design standards — and which reach first for the medicine cabinet of new weight-loss drugs? The equity warning will be tested in real budgets.
3. Development assistance flows: With sub-Saharan Africa forecast to bear 70 per cent of the burden from collapsing health aid, watch donor-country budget decisions this winter — they are now, in the Commission’s arithmetic, direct determinants of global survival.
4. Education funding: The 16.1 billion DALYs tied to educational attainment put girls’ education funding on the global-health agenda in hard numbers. Watch the pledges at the next replenishment rounds of global education funds.
5. The interconnection clause: The Commission insists the threats cannot be addressed in isolation. Watch for the first major government or multilateral body to reorganise its threat planning around this framework — merging health, climate, security and economic foresight into one process.

Sources

• The Lancet — 21st Century Global Threats to Health (journal reference)
• World Health Summit 2026, Berlin
• News-Medical — Lancet Commission identifies seventeen catastrophic threats to global health
• HealthAndMe — ‘Humanity Can Still Act’: Lancet Warns Of 17 Global Health Threats By 2100