The number of overweight and obese people in the developing world more than tripled between 1980 and 2008, according to a study released Friday -- numbers that the study’s author says is evidence that bigger purchasing power often translates into bigger waistlines.

According to the report released by the Overseas Development Institute, a U.K. think tank, the number of overweight or obese people in the developing word skyrocketed from 250 million in 1980 to 904 million in 2008.

By contrast, the number of overweight and obese people in high-income countries increased 1.7 times over the same period, reaching 557 million.

Steve Wiggins, the study’s author, says the most dramatic increases have been seen in middle-income countries. The study shows that Latin America, North Africa and the Middle East, for example, had roughly the same percentage of obese and overweight adults in their population in 2008 as did Europe, at roughly 58 per cent.

“We’re seeing a middle class emerging which helps the power of the wallet, and a more varied and interesting diet,” Wiggins told CTV News Channel on Friday. “People are going for more livestock, more dairy products, meat, fish and so on. But in amongst all of those, there are foods that have a relatively high fat content, quite a lot of sugar, particularly when you get into the processed food.”

Wiggins says these foods, combined with a more sedentary lifestyle, often leads to obesity.

Wiggins added that one huge obstacle at stemming the rise in obesity rates is a limited interest by policy makers.

“As you can imagine in developing countries there are other issues,” he said. “And this is a problem which is below the radar. It doesn’t breakout headlines and are not events that catch policy makers’ attention.”

But rising obesity rates are clearly not limited to developing countries -- it’s just rising at a faster rate. As a percentage of population, North Americans are still the most overweight and obese people in the world. Most estimates say that nearly 70 per cent of adults in North America are either overweight or obese.

The ODI study said that globally the percentage of overweight and obese people rose from 23 per cent in 1980 to 34 per cent 2008.

Wiggins said the numbers suggest that policy makers everywhere need to push for more policies that directly address the issue, even possibly taxing some of the unhealthiest foods.

“This (overweight and obesity rate) is steadily creeping up year by year and we are not absolutely sure at what point it’s going to stop,” he said. “Other than perhaps reaching 100 per cent.”