The use of ethanol as a fuel source is not a wise decision. This is because the energy extracted from the food is not great enough to justify the cost of eliminating food for fuel. The fuel limits the supply of corn for human consumption and thus drives up the price in the marketplace.
Corn ethanol has contributed to the rising cost of corn in recent years. However, this rise in cost has effects beyond just the cost of corn. Corn is used as animal feed, and the rise in cost of feed is also passed along to the consumer when he buys meats. The world probably grows enough corn that supply is not too much of an issue, but using part of the supply for ethanol production indisputably affects food prices.