We tend to think of obesity as a rich-country problem, but for several years now evidence has been building that the public-health hazard is assailing low- and middle-income countries as well, even as these same countries struggle with high rates of malnutrition. In perhaps the most comprehensive snapshot yet of this phenomenon, a study published in The Lancet on Thursday found that one-third of the world's population is now overweight or obese, and 62 percent of these individuals live in developing countries.
The graph below shows how the prevalence of overweight and obese men and women has risen between 1980 and 2013 in the developing and developed world, and as a whole. The research team—led by the Washington-based Institute for Health Metrics and Evaluation and funded by the Bill & Melinda Gates Foundation—defined "overweight" adults as those with a body mass index (BMI) between 25 and 30, and "obese" adults as those with a BMI of 30 or more.
These across-the-board increases translate into the global overweight and obese population ballooning from 857 million in 1980 to 2.1 billion in 2013. Men tend to have higher obesity rates in developed countries, and women tend to have higher rates in developing countries.
Obesity isn't just spreading to the developing world; it's also concentrating in certain places. According to the Lancet study, more than half of the world's 671 million obese people live in just 10 countries: the United States, China, India, Russia, Brazil, Mexico, Egypt, Germany, Pakistan, and Indonesia. The U.S. accounts for 13 percent of the world's obese population, and China and India a combined 15 percent.