An extract from the World Naked Bike Ride book:
Oil is also used to produce the very food we eat, even if we don't eat the oil directly. Think about what fuels the tractors to plough the ground and manage the ground during the year: manuring, seeding, weeding, harvesting. Then consider where we get the energy required to drive the process, to grind the corn, wheat, rape and other crops; the fuel to chop the trees to produce the packaging of the processed food. Consider how the raw foodstuffs, and then the finished products, are transported from factory to shop, and in turn to our homes, having been paid for with a plastic card, before being eaten with perhaps metal cutlery on ceramic tableware. The metal knife, fork and spoon, will have been produced at a factory by a machine which required oil to function, probably the ceramic plates too. The semi- and liquid effluent is almost certainly sluiced down oil-based piping to a further processing plant. Finally the solid rubbish is thrown into probably oil-based plastic containers or waste bins and transported to the dump by oil-driven machines, to be crushed by giant earth moving vehicles, powered by..., yep, you guessed it, yet more oil.