It's very, very naive to think that you can simply put all the recommended dosages of vitamins and macro-/micro- elements into a single shake and have it fulfil

It's very, very naive to think that you can simply put all the recommended dosages of vitamins and macro-/micro- elements into a single shake and have it fulfil all the nutritional needs. You need enzymes to digest food, specific enzymes and specific chemical conditions for absorbing specific nutrients, and you can not intake all nutrients from a single portion of food because, well, physics happens. There is a fundamental need of the human body for variety in food intake. You can get some idea of how complicated this gets from reading papers on some commonly known patterns of nutrient interaction, like copper+zinc: http://www.ncbi.nlm.nih.gov/pubmed/3625315 http://www.ncbi.nlm.nih.gov/pubmed/3625315 http://jn.nutrition.org/content/130/5/1378S.full http://jn.nutrition.org/content/130/5/1378S.full