The number of obese children and adolescents around the world rose to 124 million in 2016 - more than 10 times higher than the 11 million classified as obese 40 years ago.
A further 213 million children and adolescents were overweight in 2016, finds a new study published in the Lancet.
Looking at the broader picture, this equated to roughly 5.6% of girls and 7.8% of boys being obese last year.
Most countries within the Pacific Islands had the highest rates globally, with more than 30% of their youth ages 5 to 19 estimated to be obese.
The US and some countries in the Caribbean as well as the Middle East came next with levels of obesity above 20% for the same age group.
"Over the past four decades, obesity rates in children and adolescents have soared globally, and continue to do so in low- and middle-income countries," said Majid Ezzati, professor of global environmental health at Imperial College London in the UK, who led the research.
Over the same time period, the rise in obesity has particularly accelerated in East and South Asia.