The Institute for Health Metrics and Evaluation (IHME) in Washington published what researchers called the most comprehensive study on the subject. They gathered data from surveys, the World Health Organization (WHO), various government websites, and read all academic articles about the spreading epidemic. Anyone with a body mass index (BMI) over 25 was considered overweight and anyone over 30 was considered obese.
Researchers studied data from 1980 to 2013, and during that time period the number of overweight and obese people jumped from 857 million to 2.1 billion.
The U.S. counts for 5 percent of the global population with about 318 million people, yet accounts for 13 percent of obese population. China and India combined -- the world's two largest populations -- only hold 15 percent of the world's overweight and obese population. According to the CDC, about a third of adults in the U.S. are obese and another third are overweight.
The U.S. was followed in order by China, India, Russia, Brazil, Mexico, Egypt, Germany, Pakistan, and Indonesia on the list of the most overweight people.
"Over the past decades the modernization of our world, with all the technology around us, has led to physical inactivity on all levels," said Professor Hermann Toplak, at the University of Graz.
The researchers said the rates are highest in developed countries because of longer work commutes from the suburbs, sitting at computers all day, and unrestrained eating.
"Obesity is a complex issue that requires action at national, local, family and individual level; everyone has a role to play in improving the health and well-being of the public, and children in particular," said Professor John Newton, chief knowledge officer at Public Health England.
The study stressed the need for "urgent global leadership" to fight against risk factors such as excessive calorie intake, inactivity and "active promotion of food consumption by industry."