A variety of factors have come together to drive world food prices dramatically higher. The high cost of food is pushing many of the world's poorest people deeper into poverty. As we hear from VOA science reporter Art Chimes, experts say the causes include the high cost of oil and a growing middle class in some big countries.

Rice is a staple in many parts of the world

If you've been shopping for food lately, I don't have to tell you that prices are going through the roof. In some cases world prices have more than tripled in recent months, "going from, in December, a price of $300 a ton to just this week over $1,000 a ton."

Robert Zeigler of the International Rice Research Institute is talking about rice, a basic staple food across Asia, of course. Prices surged dramatically after China, Vietnam, and India curbed exports to ensure they had enough supplies for their own people.

Other food products have also seen alarming increases.

The U.N.'s Food and Agriculture Organization, the FAO, says wheat prices have doubled in Senegal. Bread prices doubled in Tajikistan. The cost of maize in Uganda rose 65 percent in just six months.

One reason: farmers are passing on their higher costs, particularly the rising cost of energy.

"Fertilizers become more and more unaffordable for the small farmers, who are at the center of a response to the world food crisis," notes Joachim von Braun, who heads the International Food Policy Research Institute in Washington. "And transport costs have become higher and higher, so the cost side of agriculture will keep food prices high, even if we make major efforts to increase production."

Other reasons for the run-up in prices include natural causes like drought and pest outbreaks and speculation in the commodities market.

And as world oil prices hover around $120 a barrel, more food crops are ending up in fuel tanks. In the United States, about one-quarter of the corn crop is now being used to make ethanol, which is blended with gasoline to make a motor fuel. Soybean farmers are switching to corn, which drives up soy prices, and so on.

Rising living standards also play a role. Particularly in India and China, where hundreds of millions of people are getting their first toehold on the middle class, more people are buying more food higher up the food chain, says Carlos Seré of the International Livestock Research Institute in Nairobi.

"We know that consumers, when they move, let's say, from $2 to $10 a day per capita, they largely expand the consumption of vegetables, oils, and animal products. This is happening in big countries around the world. This has a big impact."

But in many cases the poorest of the poor are paying the price for the good fortune of the emerging middle class.

Analysts like Robert Zeigler of the Rice Research Institute are starting to assess the damage. "Now what are the consequences of this? Well, there are some estimates that say that if present trends continue for very long, we can expect 100 million people to be pushed back into poverty."

And Joachim von Braun of the Food Policy Research Institute says that higher food prices today can cause long-term damage as people change their eating habits.

"The high food prices lead poor people to limit their food consumption and shift to even less balanced diets with harmful effects on health in the short and long run. The child [who] is not appropriately nourished under the age of three for a couple of months will be harmed for the rest of its life."

The three experts spoke in a telephone briefing organized by the Consultative Group on International Agricultural Research, whose member research centers have some 8,000 scientists working on food issues.