As a country gets more developed, the general populations waistlines also get larger, according to a new report from the Organization for Economic Cooperation and Development. 

The report found that over the past five years obesity increased by 2 to 3 percent in Australia, Canada, France, Mexico, Spain and Switzerland. In England, Italy, Korea and the United States obesity levels remained about the same.

On average, 1 in 5 children is overweight in OECD countries, but obesity rates were 1 in 3 in countries such as Greece, Italy, Slovenia and the United States.

A review of available data showed that the global recession that struck in 2008 forced many families in harder-hit nations to cut back spending on food, especially healthier but often more expensive options such as fruits and vegetables, in favor of cheaper, less healthy options, it said.

"The economic crisis is likely to have contributed to further growth in obesity," OECD researchers wrote.

Although the overall rate of obesity has slowed among more economically developed countries over the past five years, "the obesity epidemic has not stopped spreading," they added.

The new report, based on a review of data from 10 OECD countries, will be presented on Wednesday at the European Congress on Obesity in Bulgaria.

Some countries adopted policies to address obesity. Mexico created a comprehensive government strategy to address obesity last year that included awareness-raising, healthcare, regulatory and fiscal measures, the report said.