The number of obese and overweight people in the developing world has nearly quadrupled to almost a billion between 1980 and 2008, Agence France-Presse reported.

According to the Overseas Development Institute, there are now far more obese or overweight adults in the developing world than in richer countries.

The London-based institute said more than a third of all adults around the world -- 1.46 billion people -- were obese or overweight. The number of people affected in the developing world rose from 250 million to 904 million between 1980 and 2008. In the developed world, the figure rose from 321 million to 557 million, AFP reported.

"The growing rates of overweight and obesity in developing countries are alarming," said ODI research fellow Steve Wiggins, who co-authored the Future Diets report. "On current trends, globally, we will see a huge increase in the number of people suffering certain types of cancer, diabetes, strokes and heart attacks, putting an enormous burden on public healthcare systems."

Overweight and obesity rates have almost doubled in China and Mexico since 1980, and risen by a third in South Africa, the report stated.

According to AFP, the study said the rise in obesity was down due to diets changing in developing countries where incomes were rising, with people shifting away from cereals and tubers to eating more meat, fats and sugar.

The over-consumption of food, coupled with increasingly sedentary lives, was also to blame, AFP reported. Public and leaders were portraying little will in taking action on influencing diet in the future, according to the report.

"Governments have focused on public awareness campaigns, but evidence shows this is not enough," Wiggins said. "The lack of action stands in stark contrast to the concerted public actions taken to limit smoking in developed countries. Politicians need to be less shy about trying to influence what food ends up on our plates. The challenge is to make healthy diets viable whilst reducing the appeal of foods which carry a less certain nutritional value."