Global food prices have been on an upswing and have soared almost 45 % over the past year even as surging oil prices make growing and transporting food even more expensive.

Ramped-up production of bio fuels, particularly in the U.S., also is taking an increasing share of the world's food production, and droughts and floods possibly linked to global warming have slashed harvests in leading grain producers such as Australia.

 There have been riots in the African nations of Burkina Faso, Mauritania, Mozambique and Senegal. Rising prices have hit poor countries like Haiti and Peru and even developed countries like Italy and the United States.