More than 220 million children worldwide could be living with obesity by 2040 unless urgent action is taken, an international report has warned.
New figures from the World Obesity Federation show a sharp rise from current levels. In 2025, an estimated 180 million children globally were classified as obese. By 2040, that number is projected to reach 227 million among 5 to 19-year-olds, with more than half a billion children expected to be overweight.
According to the federation’s 2026 World Obesity Atlas, at least 120 million school-age children are likely to show early signs of chronic disease linked to high body mass index (BMI).
A BMI of 30 or above is classed as obesity, while a BMI over 25 is considered overweight.
Johanna Ralston, the federation’s chief executive, said the figures reflected a global failure to treat obesity as a serious disease. “It is not right to condemn a generation to obesity and the chronic and potentially fatal diseases that often go with it,” she said.
The report shows stark differences between countries. In the United States, about 27 million children aged 5 to 19 have a high BMI, second only to China, with 62 million, and India, with 41 million. In the US, this equates to around two in five children being overweight or obese.
In the UK, approximately 3.8 million children have a high BMI, the highest level on record. The UK now ranks among the worst-performing countries in Europe, with roughly double the proportion of overweight and obese children seen in France and Italy.
The report estimates that by 2040, around 370,000 children aged 5 to 19 in the UK will show early signs of cardiovascular disease, while 271,000 are expected to show signs of hypertension.
Significant regional inequalities were also highlighted. The 10 countries where more than half of school-age children are overweight or obese are all located in the western Pacific region or the Americas. Meanwhile, the fastest growth in obesity rates is occurring in low- and middle-income countries.
The federation called for stronger measures to create healthier environments for children. These include sugar taxes, tighter restrictions on junk food advertising and policies designed to increase physical activity.
Global health experts said the findings should prompt urgent political action. Dr Kremlin Wickramasinghe, a regional adviser at the World Health Organization in Europe, described childhood obesity as a “failure of environments”.
He argued that voluntary measures were not enough and called for mandatory marketing restrictions and clearer front-of-pack food labelling. “Many governments, including in Europe, are allowing the food industry to target children without restriction,” he said.
Katharine Jenner, executive director of the Obesity Health Alliance, said childhood obesity was preventable. She warned that rising rates of early heart disease and hypertension should act as a “wake-up call” about the long-term effects of inaction.
A spokesperson for the Department of Health and Social Care said the government was taking steps to address the issue. Measures include restricting junk food advertising on television before 9pm and online, alongside granting councils stronger powers to block fast food outlets near schools.
