Berlin (dpa-AFX) - Nearly a third of the world's population is overweight or obese, according to a study using data from more than 180 countries.
The 857 million people that were overweight in 1980 increased to 2.1 billion in 2013 - appreciably faster than the rise in the world's population, according to the study "Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013."
Conducted by the University of Washington's Institute for Health Metrics and Evaluation (IHME) and published in the British journal The Lancet, the study states that the development applies equally to industrial and developing countries.
More than half of overweight people live in 10 countries, which include the US, China, India, and Germany, it adds.
As a measurement of excess weight, the scientists in the study used body-mass index (BMI), which relates a person's height to weight by dividing weight in kilograms by the square of height in centimetres. Overweight is defined as a BMI of between 25 and 29.9, while obesity or adiposity is 30 or higher.
"Obesity is an issue affecting people of all ages and incomes, everywhere," said IHME director Christopher Murray.
From the total of 671 million people who have a BMI of 30 or higher, the vast majority live in the US. The largest rise in obesity over the past three decades were in the Middle East - namely Egypt, Saudi Arabia and Oman.
The researchers are especially concerned that more and more children and young people are overweight or obese.
"We know that there are severe downstream health effects from childhood obesity, including cardiovascular disease, diabetes, and many cancers," said the study's lead author Marie Ng. "We need to be thinking now about how to turn this trend around."
In an accompanying commentary to the study, medical doctor Klim McPherson of Oxford University extols the work of Ng and her colleges.
Stating that although the study's underlying data are "somewhat obscured" by the researchers' statistical methods, McPherson said the report's "truth is not."
"Politicians can no longer hide behind ignorance or confusion," he said, called more to be done against obesity.
Next to poor nutrition and too little exercise, other factors contributing to excess weight and obesity include certain medications, stress, lack of sleep and genetic predisposition.