Has there ever existed (or been interest in creating) a 'perfect' food that would fulfill all the dietary requirements of a human? The 'Bachelor Chow' from Futurama comes to mind here, a bland, colorless cereal that has all the proteins, vitamins, minerals, carbs, calories, et al that we need to survive.
Would such a thing even work? Would drinking say, two or three cans of miracle liquid a day as your only source of food have serious complications involved with it?