By Scott Kilman - The Wall Street Journal

The soaring cost of food increased the number of hungry people in the world by 122 million in 2007 and now threatens to swell the malnourished population for a decade, the U.S Department of Agriculture added.

According to the department's annual food security assessment, 982 million people were hungry last year, up 14% from a revised estimate of 860 million in 2006. The number of new hungry people - the biggest increase since the department started producing the report of 16 years ago - is roughly the population of Japan.

A year ago, USDA economists predicted food insecurity would shrink as a problem in every region except sub-Saharan Africa.

In the new assessment of 70 developing countries USDA economists project that the number of malnourished will climb to 1.2 billion people by 2017. A year ago, the economists saw that the number falling to about 800 million over a decade.

The leaders of rich nations are watching the worsening hunger situation. Food riots have broken out in several poor countries.

Food prices are climbing around the world because farmers can't keep up with demand for grain. The biofuels boom in the U.S and the new Asian Middle class's appetite for grain fed meat have combined to drain world grain stockpiles. Since January 2007, the USDA's index of all crop prices has climbed 44%.