Over one billion people around the world are obese.
Global estimates published in The Lancet include 880 million adults and 159 million children, according to data from 2022.
The highest rates of obesity are in the Pacific islands of Tonga and American Samoa for women and American Samoa and Nauru for men, with between 70 and 80 per cent of adults living with the medical concern.
The team of experts say the results show an urgent need for wholesale changes in the way obesity is tackled.
Professor Majid Ezzati, a senior researcher at Imperial College London, told the BBC: "In many of these island nations it comes down to the availability of healthy food versus unhealthy food.
"In some cases there have been aggressive marketing campaigns promoting unhealthy foods, while the cost and availability of healthier food can be more problematic."
Professor Ezzati explained that he has been taken aback by the speed at which the crisis has escalated as many more countries face an obesity epidemic.