Obesity rates levelling off and even declining

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Obesity rates levelling off and even declining in many nations, says global progress report.

A new analysis of global obesity trends since the 1980s reveals rising levels of obesity have slowed, stabilised and possibly even reversed in many nations, challenging the idea of a ‘global epidemic’ of obesity.

The work, led by researchers from Imperial College London via the NCD Risk Factor Collaboration (NCD-RisC) and published in the journal Nature, looked at more than four decades of health data from 200 countries and territories, covering the period from 1980 to 2024.

The findings come as experts from around the world meet at the European Congress on Obesity (ECO 2026) in Istanbul this week, and provide a more optimistic picture of progress than previously reported.

They show that the increase in obesity rates has slowed or levelled off in most high-income countries despite rapid rises at the end of the 20th Century, slowing first in school-aged children followed by a slowdown in adults about a decade later. In some high-income countries (including France, Italy and Portugal) rates may have even begun to decline.

According to the researchers, these latest findings suggest that previous claims of a ‘global epidemic’ of obesity are likely an oversimplification and mask the huge diversity seen across countries – which can be driven by a range of factors, especially the availability and affordability of healthy foods.

However, they highlight that obesity prevalence continues to rise in many low‑ and middle‑income countries, particularly in Africa, Asia, Latin America, and Pacific and Caribbean island nations.

“There has been real progress on childhood obesity in parts of Europe and around the world, but we cannot become complacent.”

The researchers say that by focusing on the pace of change in obesity over time, rather than just the prevalence, we can learn where urgent action is needed, including robust health and food policies to help nations adapt and manage public health during economic, technological and nutritional transitions.

Professor Majid Ezzati, from the School of Public Health at Imperial College London and Academic Director of Imperial Global Ghana, who led the analysis, said:

“We’ve been analysing obesity trends for decades and have shown that on the whole, obesity has increased – with more people being affected by overweight and obesity.

“This latest analysis suggests that the rate of growth in obesity is slowing and stabilising, and may even be reversing, in many countries. This offers a more optimistic picture that progress is being made and challenges the widely accepted view that we’re experiencing a global epidemic of obesity – which may be an oversimplification of the diversity of the situation in different countries. By focusing on the rate of change, we can better understand and benchmark the progress of nations in preventing and tackling obesity – so not just where we are right now, but where we’re headed.

“We now need to find out why some countries are doing so much better than others and apply the lessons to stop obesity from increasing. Ultimately, this analysis shows that the trend towards obesity is not inevitable, and that it is possible for policy makers to intervene to stop and even reverse growing obesity.”

Dr Jennifer Baker, President-Elect of the European Association for the Study of Obesity & Center for Clinical Research and Prevention, Copenhagen University Hospital, said:

“There has been real progress on childhood obesity in parts of Europe and around the world, but we cannot become complacent. Levels remain too high, and globally the picture is strikingly uneven, with continued increases in some countries.”

Global trends

Previous reports on the global state of obesity, including those conducted by NCD-RisC in collaboration with the World Health Organization (WHO), have typically compared prevalence of obesity over decades. According to the researchers, while this provides valuable insights, the approach can make it difficult to track progress in controlling obesity, especially recent changes that reflect policy innovation.

In the latest analysis, researchers used velocity of obesity as a key measure – calculated as the annual absolute change in prevalence of obesity and reported in percentage-points-per-year. Using this method, they were able to provide a clearer picture of where increases in obesity are accelerating, stabilising, or reversing.

The team analysed weight and height measurements from over 232 million people aged five years or older (70 million people aged five to 19 years, and 162 million aged 20 years or older), representing 200 countries and territories.

More than 1,900 researchers contributed to the study, which looked at body mass index (BMI) to understand how obesity rates have changed worldwide from 1980 to 2024. Obesity was defined as a BMI ≥30 kg/m2 for adults and BMI >2 standard deviations (SD) above the median of the WHO growth reference for children and adolescents. Estimates of obesity were adjusted for differences in how the population was distributed in different ages through a process called age standardization.

Children improving first

Among the key findings to emerge is that improvements in high-income countries were typically first seen among children and adolescents, followed around a decade later by adults. In most high-income western countries, the rise in obesity among children occurred before the millennium, with this trend slowing, plateauing and even reversing slightly from the year 2000.

Denmark experienced the earliest documented slowdown (around 1990), followed by other European countries including Iceland, Switzerland, Belgium and Germany during the 1990s. By the mid-2000s, growing obesity rates among school-aged children and adolescents in most high-income countries started to stabilise and in some even started to decline. The exceptions were among children in Australia, Finland and Sweden, where obesity increased steadily or accelerated.

However, the levelling off has happened at very different national prevalences across countries. In many western European countries and Japan, obesity growth plateaued or reversed when prevalence was below 10% of the school-age population (i.e. where fewer than one in ten children had obesity). By comparison, in the USA and New Zealand, obesity stabilised when levels were much higher, at 19-23% of the school-age population (i.e. where as many as one in four school children had obesity). The same trend was seen in adults.

Global divide

In contrast to the signs of progress, the analysis also highlights that obesity continues to rise, and is even accelerating, in most low- and middle-income countries.

This divergence from the progress seen in high-income nations highlights growing global inequalities in nutrition and health. The researchers highlight the need for tailored public health policies to address the growing gap – including those focused on the availability and affordability of healthy foods for countries and communities who cannot currently afford and access them.

Over the last decade, new obesity medications have become widely available, including GLP-1 Receptor Agonists (such as liraglutide and semaglutide). The researchers state that the introduction of these drugs does not yet explain the changes seen in their study, but add they will likely play an important role in future trends, especially if access and affordability are improved.

Professor Ezzati explained: “At this stage it’s probably too early to say whether GLP-1 drugs have had a direct impact in entire populations, even though they are beneficial for patients who use them. The focus should be on making them more affordable to all who need them around the world.”

The authors highlight a number of limitations to the study, including the amount of data available, which varied by region.

The research was funded by the UK Medical Research Council and UK Research and Innovation (UKRI), and supported by funding through the European Union.