The Overseas Development Institute (ODI) said that the number of people affected in the developing world almost quadrupled between 1980 and 2008 to nearly one billion. In the UK, some 64% of adults are overweight or obese, classed as having a body mass index greater than 25.
The ODI warned of a huge increase in health-related problems such as heart attacks, strokes, cancers and diabetes.
It suggested that changing diets and over-consumption of food linked to increased prosperity in the developing world was largely behind the change. As incomes increase, diets are shifting from cereals and grains to a greater consumption of meats, fats and sugars.
The ODI's Future Diets report found that globally, the percentage of adults who were overweight or obese grew from 23% to 34% between 1980 and 2008.
Some 904 million people in developing countries were classed as overweight or obese in 2008, almost four times the 250 million in 1980.
By contrast, the number of people who were overweight or obese in high-income countries increased by 1.7 times over the same period.
At the same time, under-nourishment is still a problem for hundreds of millions of people.
"The over-consumption of food, coupled with lives that are increasingly sedentary, is producing large numbers of people who are overweight and obese - primarily in high-income countries, but also in emerging middle-income countries," the report said.
"Indeed, the world has seen an explosion in overweight and obesity in the past 30 years."