You'll probably know America as the land of the free, and fat. But the country is gaining competition from other countries with increasing waistlines.

A new report by the Overseas Development Institute (ODI) tracked this progress, and digs into the factors behind the shit: rising incomes, urbanization, reduced physical activity, and the popularity of foods high in fat, sugar, and salt.

The percentage of adults who were obese or overweight between 1980 and 2008 went from 23% to 34%, with the majority of that increase coming in low-income countries. The developing world saw the number of obese or overweight increase almost four times (from 250 to 904 million people) over this period, while the developed world saw an increase of only 1.7 times.

When people became richer, their diets tended to shift from grains and starchy staples, to more vegetables, animal produce, and oils.

ODI illustrated its main findings in the graphics below:



The good news is that not all prospering countries have become fatter. For example, South Korea has dodged the trend, mostly due to its public campaigns and training to encourage women to continue cooking traditional meals.