For the first time, more children worldwide are living with obesity than being underweight, according to new Unicef research. The study shows nearly one in ten children and adolescents aged five to nineteen – around 188 million globally – are now obese. Researchers link this to a growing reliance on cheap, ultra-processed foods high in sugar, fat, and salt, which are replacing traditional, healthier diets.

While undernutrition, particularly stunting and wasting in under-fives, remains a challenge in many low and middle-income countries, the balance is shifting. Since 2000, underweight prevalence in older children has dropped from nearly 13% to 9.2%. In the same period, obesity has tripled from 3% to 9.4%. Today, around one in five school-aged children are overweight, amounting to an estimated 391 million worldwide.

The impact is felt across regions. Obesity rates surpass underweight in almost every part of the globe, with the exception of South Asia and sub-Saharan Africa. Small Pacific Island nations face the steepest crisis, with obesity rates above 30% in some. Wealthier nations are also heavily affected, with more than a fifth of children classed as obese in countries such as the US, Chile, and the UAE.

Unicef warns of both health and economic fallout if action is not taken. By 2035, the global financial burden of obesity could top US$4 trillion annually. The agency is urging governments to act decisively – from taxing unhealthy food and drink to banning ultra-processed products from schools, reformulating products, and ensuring food policy remains free from industry interference.