It's a small world, but we're all getting bigger!

It may be a small world, but the world's population is quickly gaining weight. That's according to recent estimates by the World Health Organization, which recently ranked countries by percentage rates of obesity. While it may surprise you that the United States came in at the bottom of the top 10, (who else had us pegged at number one?), it's actually the influx of Western food and lifestyle that seems to be contributing to the widening waistbands in other countries.

Countries that are the hardest hit by this trend are in the South Pacific. As ties between the countries in this area and Westernized countries like the U.S. and New Zealand strengthen, the region sees more and more imports of processed foods heavy in fat in sugar. Urbanization is another culprit. People move away from their rural lifestyles, and away from the heavy labor and local food supply as well. These types of changes put countries like Nauru, with 94.5% of its adult population overweight, at the top of the list.

Experts warn that you really can't compare obesity rates country by country, but it's important to note that the trends are rising across the board. For a list of the "world's fattest countries," go here.