Obesity trends are rising faster in low and middle-income countries, even as they may have plateaued in high-income ones, a study has shown.
The analysis, published in the journal Nature, looked at data from 232 million individuals across 200 countries and territories over the last 45 years. More than 4,000 population-based studies that carried height and weight data of the participants were analysed to assess global dynamics of obesity during 1980-2024.
Researchers forming the Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC) said that for almost all countries, obesity rates have increased over the study period, but trends varied across populations.
"The rise in obesity decelerated in school-aged children and adolescents throughout the 1990s in many high-income countries, and subsequently plateaued in most at age-standardised prevalences spanning 20 percentage points, from 3-4 per cent for girls in Japan, Denmark and France to 23 per cent for boys in the USA," the authors wrote.
"In most low-income and middle-income countries, the annual absolute change in prevalence has remained stable or increased over time, even though prevalence has surpassed that of high-income countries," they said.
The highly varied dynamics suggested that the social, economic and technological trends influencing the availability and affordability of foods may have helped control the rise in obesity in high-income countries, but require policy interventions in low-income and middle-income countries, the team said.
They added that understanding trajectories in a detailed manner may help identify interventions and policy changes to address obesity in varied countries.
Obesity is more prevalent now than it was at the end of the twentieth century, with the term 'epidemic' often used to describe its rise.
In Western Europe, prevalence of obesity was found to have stabilised at 11-23 per cent for adults and 4-15 per cent for children and adolescents -- the earliest slowdown was seen around 1990 in Denmark, followed by countries including Iceland, Switzerland, Belgium, and Germany through the 1990s.
However, obesity has increased sharply in low and middle-income countries, reaching a prevalence of 30-40 per cent among adults in countries in Central Europe -- for example, Romania and Czechia -- and Latin America, such as Brazil.
The analysis also revealed that rising obesity trends slowed down among adults in high-income western countries about a decade after they did in children.
However, differences between men and women, such as whether or when obesity plateaued, were found to be country dependent.
Identifying trends in obesity may help explain underlying factors, which could inform policies address and curb its rise, the authors said.