For years, food policy in the Middle East and North Africa was very simple: hydrocarbon exports paid for carbohydrate imports. Rising agricultural commodities prices and a large population increase mean that the traditional policy is now untenable even if crude oil trades at about $120 a barrel, forcing countries in the region, including Saudi Arabia, to reconsider how it feeds its population. "The region has woken up to the new food market reality," says Abdolreza Abbassian, an expert at the Food and Agriculture Organisation in Rome.

Record global food prices will be on the agenda of the Group of Eight heads of state summit in July for the first time in almost 30 years, amid mounting concerns about the social, political and economic impact of the food crisis. The International Monetary Fund on Monday gave its starkest warning about the impact of rising commodities, saying food and oil prices "risk becoming a destabilising force in the global economy'. Yasuo Fukuda, Japan's prime minister, said in a letter to his G8 colleagues that soaring food prices were posing "imminent and serious' global challenges.

The Organisation of the Petroleum Exporting Countries has quietly begun to reduce its oil production despite calls from the US and Europe for the group to pump more so that prices fall. Output from the core countries of the 13-member cartel last month fell to 27.3m barrels a day, down from the 27.6m b/d they produced in February and 27.8m b/d in January, the International Energy Agency, the western countries' watchdog, said yesterday in its monthly report. Production from Saudi Arabia, Opec's largest member, dropped marginally from January and was the same as February at 9.2m b/d.

For the past 40 years, consumers have had the upper-hand in the global rice market, which has witnessed a steady decline in prices, interrupted only by the brief spike in 1973-74 triggered by the first oil crisis. The structural decline in prices was the result of the Green Revolution, the agronomics movement that spread the use of irrigation, fertiliser and high-yielding varieties of rice in Asia in the late 1960s and led to bumper crops.

The rising cost of basic foods risks wiping out a decade of efforts to combat global -poverty and could trigger further riots in the world's poorest countries, leading multilateral institutions warned yesterday. The World Bank, the Food and Agriculture Organisation and the International Monetary Fund were unanimous in concluding that the rising appetite of the bio-fuels industry was part of the reason for the increase in food prices.

Rising food prices could spread social unrest across Africa after triggering riots in Niger, Senegal, Cameroon and Burkina Faso, African ministers and senior agriculture diplomats have warned. Kanayo Nwanze, the vice-president of the United Nations' International Fund for Agriculture, told a conference in Ethiopia that food riots could become a common feature, particularly after the price of rice has doubled in three months. "The social unrest we have seen in places such as Burkina Faso, Senegal or Cameroon may become common in other places in Africa," Mr Nwanze said.

Saudi Arabia plans to halt wheat production by 2016 because of concerns about the desert kingdom's scarce water resources, according to a US government agency. The Saudi Arabian government has not publicly given details of the move, which comes as global cereal prices surge, driven by strong demand and lagging supply. Top-quality wheat prices for baking bread hit a high this week of $25 a bushel and have more than doubled since January.