The World Food Program of the United Nations says there are increasing concerns over the supply of food, especially in the developing world.

The WFP is drawing attention to the latest report on the State of Food Security in the World, which says volatility in food costs and high, unpredictable prices are likely to continue.

The WFP says rising food prices, weather emergencies and political instability are making it increasingly more difficult for families to feed themselves. This is especially true in Africa, where many nations, dependent on imports, are affected by food and economic crises.

Gregory Barrow, a WFP official, says populations in developing countries might be spending as much as 80 percent of their incomes on purchasing food.

The situation in Haiti is also highlighted. The impoverished Caribbean nation continues to struggle from the devastating effects of the January 2010 earthquake.

Sunday is World Food Day. The WFP, the U.N. Food and Agriculture Organization and the International Fund for Agricultural Development will mark the occasion at the FAO’s headquarters in Rome, Italy on Monday.