If you're choosing Subway in an attempt to lose some unwanted poundage, you may want to rethink your diet plan, according to researchers who have established an association between the number of the sandwich shop's chains and a country's obese population.

Findings published in the online journal Critical Public Health were drawn from around 100,000 people per each restaurant who were over the age of 15 and from one of the 26 countries with advanced economies. Subway was chosen for the basis of this study after it surpassed McDonalds as the largest fast food restaurant chain in the world.

The results of the analysis showed that countries with the highest number of restaurant chains, such as the United States and Canada, were also home to the most obese populations. While the U.S. averaged 7.52 Subway chains per 100,000 citizens, the percentage of obese people also topped the charts at 31.3 percent of men and 23.2 percent of women.

In comparison, countries with the lowest number of Subway chains like Japan with .13 per 100,000 people and Norway with .19 per 100,000 also recorded the least obese population. In Japan 2.9 percent of men and 3.3 percent of women are considered obese and in Norway 6.4 percent of men and 5.9 percent of women suffer from obesity.

The research team did assert that their findings were not definitive and do not prove that Subway is the direct cause of obesity, just that it is associated with it.

"Although our results are preliminary and exploratory, they suggest that the diffusion of fast food outlets, and trade liberalization policies promoting their growth and expansion worldwide, may contribute to the obesity epidemic," explained the authors of the study.

"Our study also raises serious issues about the role of international financial institutions such as the WTO in promoting free trade and food market integration and calls for coordinated political actions to address what we term 'globesization', the ongoing globalization of the obesity epidemic."

R De Vogli, A Kouvonen, D Gimeno. 'Globesization': ecological evidence on the relationship between fast food outlets and obesity among 26 advanced economies. Critical Public Health. Oct 2011.