It is estimated that one in four bushels of corn from this year's U.S. corn crop will be diverted to make fuel ethanol.
"Turning food into fuel for cars is a major mistake on many fronts." said Janet Larsen, director of research at the Earth Policy Institute, an environmental group based in Washington.
"One, we're already seeing higher food prices in the American supermarket. Two, perhaps more serious from a global perspective, we're seeing higher food prices in developing countries where it's escalated as far as people rioting in the streets."
Similarly, palm oil is at record prices because of demand to use it for biofuel, causing pain for low income families in Indonesia and Malaysia, where it is a staple.
But despite the rising criticism of biofuels, the U.S. corn-fed ethanol industry enjoys wide political support because it boosts farmers, who suffered years of low prices, and that support is likely to continue.
John Bruton, the European Union's Ambassador to the United States, predicts that the world faces 10 to 15 years of steep rises in food costs. And it is the poor in Africa and, increasingly, South East Asia, who will be most vulnerable.
The director of the U.N. World Food Program, Josette Sheeran, is on a global tour in search of donations to fill a $500 million funding gap caused by the rising prices. America's largest aid program, Food for Peace, has seen its commodity prices jump 40 percent and may have to curtail donations.
But aid and many policy options available to governments for helping the hungry distort markets and cause pain elsewhere in their economies, according to proponents of free markets.
"I was involved in a government that introduced food subsidies in Ireland and we had the devil's own job to get rid of them," said Bruton, who was Prime Minister of Ireland from 1994 to 1997.
Others trust that better fertilizers and higher-yielding crops - some of them genetically modified - will keep production in line with demand.
Bruce Babcock, an economist at Iowa State University, said the rising markets are a signal to farmers that they need to raise production.
"It's actually the greatest time in the world to be a farmer around the world," Babcock said. "We are going to see fairly substantial increases in production because farmers have never had such a large incentive to increase production."
But others note that expensive seeds and fertilizers are out of reach of farmers in poor countries.
Around the beginning of the 19th Century, British political economist Thomas Malthus said population had the potential to grow much faster than food supply, a prediction that efficient farming consistently proved wrong. Now, at the beginning of the 21st century, some are revisiting his predictions.
