The obesity epidemic is global: 2.1 billion people, or about 29% of the world's population, were either overweight or obese in 2013, and nearly two out of three of the obese live in developing countries, according to a study released Thursday.
The prevalence of overweight and obese people rose by 27.5% for adults and 47.1% for children between 1980 and 2013, according to the study, led by researchers at the Institute for Health Metrics and Evaluation at the University of Washington and published Thursday in the journal the Lancet. In 1980, 857 million people were overweight or obese.
The increases in overweight and obese people "have been substantial, widespread, and have arisen over a short time," said the study, which analyzed data that included the heights and weights of people in 183 countries. Today, it said, 36.9% of the world's men and 38% of women are overweight or obese.
No nation reported a significant decrease in obesity during that period, said Christopher Murray, director of IHME. "The fact that no country has had a statistically significant reduction in the time period was a surprise," he said, showing that policies to address the epidemic haven't had an effect yet.
The study didn't examine reasons for the sharp rise, though it cited a well-known litany of possible factors: diet, physical inactivity, and one that hasn't gotten as much attention-changes in the gut microbiome that affect metabolism.
Obesity is generally thought of as a disease of prosperity. Indeed, the U.S. had the heftiest population in 2013, with 13% of the world's obese, according to the IHME study. And obesity rates are highest in the developed world.
But while North America and Europe stood out as the world's heavyweights in 1980, increases in the prevalence of adult obesity there have slowed since 2006, and now "you see the share in the rest of the world going up very dramatically," Dr. Murray said.
He cited South Africa as an extreme case: 42% of women are obese, meaning that a country battling malnutrition and a substantial burden of HIV/AIDS also grapples with chronic conditions linked to excess weight.
More than 50% of the world's 671 million obese people live in 10 countries, the study said, ranking them in order: the U.S., China, India, Russia, Brazil, Mexico, Egypt, Germany, Pakistan and Indonesia.
In Tonga, 52.4% of men are obese. More than 50% of women are obese in Tonga, Samoa, the Federated States of Micronesia, and other countries.
In 2013, 23.8% of boys and 22.6% of girls were overweight or obese in developed countries. In developing countries, 12.9% of boys and 13.4% of girls were overweight or obese. Middle Eastern and North African countries had particularly high rates of childhood obesity, the authors said.
The authors said a goal set by the World Health Organization to halt the rise in obesity by 2025 is "very ambitious and unlikely to be attained without concerted action and further research."
"I think of obesity as uniquely concerning because it's one of the top health risks, and among the top risks it's the only one going up," said Dr. Murray. Other significant risks include smoking, alcohol consumption and high blood pressure, he noted.
The study, funded by the Bill & Melinda Gates Foundation, is the most comprehensive to date on global obesity trends,examining obesity data country by country over time, he said.
Return to News Home