Fast-food restaurants like to bedazzle consumers with choice, offering a smorgasbord of different foods and drinks with varying flavours and  sizes. And yet, these options have more in common than you might think. According to a new study, this multiplicity of choice hides the fact that the overwhelming majority of American takeaway food is actually based on a single source – corn. It provides food for the animals whose meat makes up the burgers, the oil for frying chips and the syrup that bulks out fizzy drinks.

Hope Jahren and Rebecca Kraft from the University of Hawaii discovered the omnipresence of corn by chemically analysing a variety of foods from America’s top chains – McDonald’s, Burger King and Wendy’s.