Surging food prices are battering families in scores of countries, forcing some people to give up eating meat, fruit, and even tomatoes, and fueling political tensions.

With food costs consuming up to 70 percent of family income in the poorest countries, rising prices are threatening to worsen malnutrition.

Inflation has stayed moderate in the United States and Europe.

In some Asian markets, rice and wheat prices are 20 percent to 70 percent above 2008 levels, according to the U.N. Food and Agriculture Organization.

Majeedan Begum, a Pakistani mother of five, said a bag of flour for bread, the staple of her family's diet, costs three times what it did two years ago in her hometown of Multan. She can no longer afford meat or fruit.

Many governments blame dry weather and high fuel costs, but critics in India, Argentina, Egypt, and some other countries blame government policies for shortages and high prices.

No single factor explains the inflation gap between developing and developed countries, but poorer economies are more vulnerable to an array of problems that can push up prices, and many are cropping up this year.

Farmers with less land and irrigation are hit harder by drought and floods. Civil war and other conflicts can disrupt supplies. Prices in import-dependent economies spike up when the local currency weakens, as Pakistan's rupee has this year.

Costs also have been pushed up by a rebound in global commodity prices, especially for soy destined for Asian consumption.

That has prompted a shift in Argentina and elsewhere to produce more for export, which has led to local shortages of beef and other food.

The global financial crisis hurt food production in some countries by making it harder for farmers to get credit for seed and supplies.

In Mauritania in West Africa, rice prices doubled over the first three months of the year, according to the World Food Program. Over the same period, the price of corn rose 59 percent in Zimbabwe and 57 percent in Mozambique.

In Kinshasa in the Democratic Republic of Congo, Mami Monga pays $25 for a box of fish that cost $10 a year ago. "Today I am obliged to buy half the food I used to buy mid-last year," said Mami.

World Food Program spokesman Greg Barrow said poorer countries could suffer a "ratchet effect" that locks in price increases because of high transportation costs and limited competition.

"Prices dropped fairly dramatically toward the end of 2008 on international markets, but we found prices remained relatively high in many local markets in developing countries," he said.

The Food and Agriculture Organization said the double blow of the global recession and high food prices had pushed 100 million people into poverty.

Opposition parties have organized protests in Pakistan.

In Egypt, a 50 percent increase in meat prices in recent weeks has fueled demonstrations outside parliament over wages and other economic issues.

Said Marta Esposito, a 45-year-old mother of two in Buenos Aires: "Tomatoes, don't even talk about it. We eat whatever is the cheapest."

In China, food costs rose 5.9 percent in April over a year ago - a modest rate for a country that had 20 percent-plus inflation in 2008.

But it was enough to prompt the anxious communist government to pledge that prices will ease as the spring harvest comes in. It also threatened to punish price gouging in a new effort to cool inflation.