DOE - Cited a new report from New Energy Finance that concludes producing 7.2 billion gallons of biofuels are "only" responsible for a 17% increase in global food prices. Noting - "The increasing price of fossil fuels caused 35.2% of the increase in grain prices."
The report concludes that population growth and fossil fuels prices placed the greatest pressure on grain prices, and that growth was not matched by increases in yields.
Sources: Energy Finance press release (PDF 16 KB)
See a summary of DOE testimony on the EERE Web site.