I think Michael Pollan described it well when he said food in America was undergoing a process of 'nutrification', i.e., breaking it down into its nutrients, and trying to create supplements with those nutrients.
The studies in the book, though, say that we haven't yet cracked the code. I.e., taking the equivalent of one apple's nutrients isn't the same as eating an apple. The reasons weren't quite known yet. I read the book a long while back, so my recollection may be spotty.