If you thought the United States was unique in its obesity crisis, you haven't been to Kuwait or Tonga recently. While the U.S. is home to 13% of the world's most overweight, many other countries are catching up fast. Obesity is no longer an exclusively first-world problem.
A major analysis of 1,769 previously published studies finds that there's been a huge tipping of the scales in the last 30 years or so. Between 1980 and 2013, the number of overweight or obese people worldwide rose from 857 million to 2.1 billion. More than 36% of men and 38% of women now have a Body Mass Index score higher than 25, the normal threshold for being overweight.
The increases were particularly steep in the Middle East and North Africa, where 58% of adult men and 65% of women are now obese or overweight, and on the Caribbean and Pacific Islands. In Kiribati, the Federated States of Micronesia, Tonga, and Samoa, more than 50% of women are obese (meaning they have a BMI over 30).
In developed countries, there are more overweight men than women. In developing countries, it's the other way around: there are more overweight women than men. The study finds that increases in developed-world obesity have flattened out in the last eight years, but are still rising elsewhere. "Our data suggest that there are likely to be continued increases in the developing world, where almost two in three of the world's obese people live," the authors say.
The study doesn't point to any single cause, though it notes the increase has been substantial and widespread, and that any theory of change has to account for a changes "over a short time."
The paper concludes:
To counter the impending health effects on populations, especially in low-income and middle-income countries, urgent global leadership is needed to help countries to more effectively intervene against major determinants such as excessive caloric intake, physical inactivity, and active promotion of food consumption by industry, all of which exacerbate an already problematic obesogenic environment.