A perfect storm of factors has driven the breathtaking rates of inflation and volatility in food markets over recent years, but biofuels have been the game changer
This year, 40% of America’s corn crop will go into car engines rather than stomachs. Add the fact that the US is both the world’s largest producer of corn and the largest exporter, and that 10 years ago only 7% of its crop went to ethanol production, and you start to see why enthusiasm for biofuelsamong oil importers has had such a marked impact on food prices.
Other factors have driven the breathtaking inflation and volatility in food markets over the last few years. These include a rising global population, millions more people shifting to western diets, declining crop yield growth, years of under-investment, extreme weather, high oil prices increasing the cost of inputs such as fertiliser, low stock levels, and kneejerk actions by governments such as food export bans and panic buying by importers.
Adorngeo's Blog 
Most of the corn raised in the U.S. is dent corn and is never intended to be used for human consumption. Do not confuse sweet corn, pop corn or even flint corn which people eat with dent corn which is an animal feed and industrial starch source.
About 1/3rd of the corn that is used for ethanol production is returned to the livestock sector as Distillers Dried Grains (DDGs). DDGs are a good source of protein for livestock. The starch is taken out to produce ethanol.
American farmers are producing more food each year with less land, less fertilizer, less chemicals, less fuel and less labor. There is no other industry that has increased it’s efficiency in so many areas. Because of the increased production of dent corn we can feed our livestock, fuel our cars and export more to the world.