A whooping one-third of the world's population is overweight or obese: Study

Almost 30 percent of the earth's population is obese or overweight, a new study reports, estimating that this affects about 2.1 billion people.

The study, which uses data from 1980 to 2013, found that the number of overweight and obese people in the world had surged in the past three decades. Although the rise in obesity rates seems to be slowing in some countries, it has yet to be reversed in any country.

"Since 1980, no country has made significant progress in reducing the rates of people being overweight or obese," Christopher Murray, the study author, said in an e-mail to Bloomberg. "Obesity is now a major public health epidemic in both the developed and the developing world."

"Countries need to be looking at how they communicate effectively both what people eat and how much they should be eating," Murray said. "Because what we've been doing up until now isn't working. Strategies to tackle obesity need to address both physical activity, total caloric intake and the different foods we eat."

More than half of the world's 671 million obese people live in the U.S., China, India, Russia, Brazil, Mexico, Egypt, Germany, Pakistan and Indonesia. During the more than three decades studied, the largest increase in obesity rates were in Egypt, Saudi Arabia, Oman, Honduras and Bahrain for women and New Zealand, Bahrain, Kuwait, Saudi Arabia and the U.S. for men.

Childhood obesity rates are notably higher in the Middle East and North Africa, particularly among girls.

Though the rate of increase in obesity has slowed in the developed world, in the developing world, home to two-thirds of the world's obese people, obesity rates are projected to continue their climb.