Wheat has doubled. Wheat doesn't compete for crop land with corn. Rice doesn't grow where corn grows. There is a huge surplus of corn in south eastern USA now. I think there is a minor impact on food from biofuels. Much of the corn used for ethanol production is grown on land farmers were previously paid to leave fallow. Based on my farming experinece (now retired), I think food shortages have extremely low correlation to biofuel production.