For years, obesity was described as a global epidemic progressing in much the same way almost everywhere. However, the latest analysis by the NCD Risk Factor Collaboration reveals a far more complex picture. In many high-income countries, the rise in obesity prevalence has slowed or plateaued. Meanwhile, in numerous low- and middle-income countries, it continues to accelerate. Poland is among the countries in Central and Eastern Europe where the trend among adults has stabilized.
The study, published in Nature, is one of the largest analyses to date of changes in obesity prevalence worldwide. The international NCD Risk Factor Collaboration (NCD-RisC) team used data from 4,050 population-based studies in which researchers measured height and weight. Altogether, these studies included 232 million people aged 5 years and older. The researchers analyzed changes between 1980 and 2024 across 200 countries and territories.
The co-authors of the publication include Prof. Tomasz Zatoński from the Department of Otolaryngology, Head and Neck Surgery, and Dr Alicja Basiak-Rasała from the Department of Population Studies and Prevention of Noncommunicable Diseases at Wroclaw Medical University. The analysis also included data from the Wroclaw cohort of the PICTURE study, led by Prof. Tomasz Zatoński and conducted by Wroclaw Medical University with co-funding from the Municipality of Wroclaw.
One epidemic, many different scenarios
Rather than simply comparing the proportion of people with obesity across successive decades, the researchers examined how the trends themselves were changing. They looked not only at how common obesity was in individual countries, but also at whether its prevalence was rising faster, slowing, stabilizing, or beginning to decline.
The results show no single global pattern. In many high-income countries, the increase in obesity prevalence among children and adolescents began to slow as early as the 1990s and subsequently plateaued in most of them. Some countries have even shown signs of a slight decline. Among adults, similar changes occurred later.
The situation is different in many low- and middle-income countries. There, the rate of increase in obesity prevalence often remains high or continues to accelerate. Moreover, in some of these countries, obesity prevalence has already reached levels higher than those observed in some high-income countries.
These differences are probably the result of multiple overlapping social, economic, environmental and cultural factors. In many low- and middle-income countries, we are seeing a very rapid nutritional and social transition. Within a short period of time, highly processed, calorie-dense foods become more widely available, patterns of work and transport change, levels of physical activity decline, while infrastructure and preventive measures do not always keep pace with the speed of these changes, explains Prof. Tomasz Zatoński.
Plateau does not mean the problem is over
One important finding from the Polish perspective is that Poland was classified among the Central and Eastern European countries where the rise in obesity prevalence among adults has reached a plateau. The researchers identified a similar pattern in Estonia, among other countries.
This is good news, but it needs to be interpreted with caution. A plateau does not mean that obesity is becoming rare. It means that its prevalence is no longer increasing at the previous rate and has stabilized at a certain level, which in some countries remains high. The study also shows that different countries reached this stabilization point at very different levels of obesity prevalence.
A plateau primarily means that the rate of increase in obesity prevalence among adults has slowed. It does not mean that the problem of obesity in Poland has been solved or that obesity prevalence is low, emphasizes Prof. Tomasz Zatoński.
The finding for Poland can therefore be seen as evidence that a further increase is not inevitable, rather than as a reason to scale back preventive measures.
This is not a signal to stop tackling obesity. On the contrary, the plateau shows that changing the trajectory is possible and that it is worth investing even more intensively in effective prevention, a healthy food environment and physical activity, adds the expert.
Adults, children, women and men may follow different paths
The analysis reveals another important pattern: no single indicator can describe an entire country. Trends differ by age and sex. In high-income countries, the slowing of the increase in obesity among children and adolescents generally occurred earlier than among adults. In some Central and Eastern European countries, however, the sequence was different, with stabilization among adults occurring before a similar change among younger people, or without such a change occurring at all. In Poland, upward trends in obesity prevalence among children and adolescents have begun to stabilize, but a slow increase continues. Among adults, by contrast, obesity prevalence has plateaued. This is also important when interpreting the situation in Poland.
The situation among adults does not necessarily reflect the situation among children and adolescents. One of the important findings of the study is precisely that obesity trajectories may differ both between age groups and between women and men, notes Prof. Tomasz Zatoński.
This means that even if the overall trend stabilizes in one group, we cannot assume the situation is improving across the entire population.
Prevention tailored to each country
The authors point out that the concept of a single “global obesity epidemic” is becoming less effective in describing reality. In 2024, countries at similar levels of development could be at entirely different stages of change. Even within the same regions, some countries had seen the rise in obesity slow, while others were still accelerating.
This is an important message for public health. A solution that works in one country may not produce the same results elsewhere if countries differ in areas such as food availability and prices, work and transport patterns, living conditions, or their capacity to implement preventive measures.
This is one of the most important conclusions of our study: obesity cannot be treated as a uniform global phenomenon following the same trajectory everywhere. Prevention strategies must also be adapted to local social, economic, cultural and environmental conditions, – concludes Prof. Tomasz Zatoński.
Poland’s plateau therefore provides grounds for cautious optimism. It shows that a long-term increase in obesity prevalence can slow down. At the same time, it does not mean that the problem is disappearing. The key question is whether this stabilization continues in the coming years and how trends develop across individual age and sex groups.
Publication:
NCD Risk Factor Collaboration (NCD-RisC), Obesity rise plateaus in developed nations and accelerates in developing nations, Nature, 2026
Obesity rise plateaus in developed nations and accelerates in developing nations | Nature