This effects the elite not so much, they don't care if their burger is $1 or $2, they make enough money. The poor people that live of a couple of bucks a day do care that their food prices have been doubled. Not to mention the robbing of land done to create palmoil plantations. So effect on the elite, they get a warm feeling inside, effect on the poor, less to eat and loss of homes and income.
McDonalds already use biofuels created from the waste oil from their kitchens. People's burgers are already cheaper precisely because of this.