The number of people in the world classified as obese has reached nearly one and a half billion.
The figure has quadrupled since just 1980, according to the UK think tank Overseas Development Institute.
This means that one in three people in the world are overweight.
'What has changed is that the majority of people who are overweight or obese today can be found in the developing, rather than the developed, world,' the report notes.
Excess weight can lead to a number of medical problems, including heart attacks, strokes, diabetes and some types of cancer.
The percentage of adults who are overweight or obese soared from 23% in 1980 to 34% by 2008, bringing the total to 1.46 billion people.
In high-income countries, some 557 million people are obese, while the developing world has a total of 904 million.
The greatest increases were seen in the developing world, especially in areas where incomes were beginning to increase, such as Mexico and China.
Extra income has led people to consume more fats, sugar, oils, meat, and processed foods instead of the stapes of cereals and grains.
The greatest percentage (70% of adults) is in North America, but Australasia and southern Latin America are catching up quickly (63%). In the UK, 64% of adults are overweight or obese.
The greatest growth in overweight people occurred in southeast Asia, where the percentage tripled from a lower starting point of 7% to 22%.
At the same time, however, under-nourishment is still recognised to be a problem for hundreds of millions of people in the developing world, particularly children.
The report lobbied for concerted public health measures from governments, even at the risk of upsetting farmers, the food industry and even the public which often view food choices as a matter of personal freedom.
