Bee Wilson in The Guardian:
For as long as people have eaten food, there have been diets and quack cures. But previously, these existed, like conspiracy theories, on the fringes of food culture. “Clean eating” was different, because it established itself as a challenge to mainstream ways of eating, and its wild popularity over the past five years has enabled it to move far beyond the fringes. Powered by social media, it has been more absolutist in its claims and more popular in its reach than any previous school of modern nutrition advice.
At its simplest, clean eating is about ingesting nothing but “whole” or “unprocessed” foods (whatever is meant by these deeply ambiguous terms). Some versions of clean eating have been vegan, while others espouse various meats (preferably wild) and something mysteriously called “bone broth” (stock, to you and me). At first, clean eating sounded modest and even homespun: rather than counting calories, you would eat as many nutritious home-cooked substances as possible.
But it quickly became clear that “clean eating” was more than a diet; it was a belief system, which propagated the idea that the way most people eat is not simply fattening, but impure. Seemingly out of nowhere, a whole universe of coconut oil, dubious promises and spiralised courgettes has emerged.