WASHINGTON, Feb. 10 (Xinhua) -- The biggest challenge facing most developing countries is the risk of a big boost in food prices, World Bank Group President Robert B. Zoellick said on Thursday.

"Food accounts for a large and increasingly volatile share of family budgets for poor and urban families. When prices of staple foods soar, poor countries and poor people bear the brunt," Zoellick said in a statement.

Costs for some basic foods are nearing or beyond the peaks of 2008. The World Bank expects volatile, higher than average grain prices until at least 2015. In the poorest countries, where people spend up to two thirds of their daily income on food, rising prices are re-emerging as a threat to global growth and social stability, according to the statement.

The Washington-based agency said there are nearly one billion hungry people worldwide, with women accounting for more than 60 percent of the world's hungry. When faced with high food prices, poor households have to eat cheaper, less nutritious food or stop using health and education services.

Global food price volatility is on the Group of 20 (G20) agenda, and Zoellick recently called for the G20 to "put food first" and advocated for steps to ensure vulnerable people and countries are not denied access to nutritious food. For the longer- term, the World Bank Group is boosting its annual spending on agriculture to the level between 6 billion and 8 billion U.S. dollars from 4.1 billion dollars in 2008, according to the statement.