To me, it seems like pretty much a new term for "whole foods," which has been around since the 70's at least. I actually prefer the term "whole foods" because "clean" sounds kind of hyper obsessive. And with the apple-to-apple pie analogy, one could have a non-whole-foods version of apple pie, with white flour, white sugar, lard or shortening, peeled apples, or a healthier, more whole foods version: whole wheat pastry flour (or barley flour, which makes a great substitution for it), unpeeled apples, sweeteners like maple syrup, stevia, molasses in lesser quantity.