Although corn-based ethanol production is expected to increase 58 percent in 2007, retail food prices are not expected to increase substantially during the same time period, according to Keith Collins, chief economist at the Agriculture Department.

Collins said U.S. food prices have increased about 7 percent so far this year. He attributed the increase primarily to bad weather that harmed fruit and vegetable production, as well as small Australia wheat crops. Collins predicted retail food prices, particularly for poultry and beef, will be slightly higher over the next few years due to growing renewable fuels production in the United States.