Is there a single definition of "clean"? The author has one definition which seems based on items commonly found on labels, like "non-gmo" or "certified organic

Is there a single definition of "clean"? The author has one definition which seems based on items commonly found on labels, like "non-gmo" or "certified organic", that gives consumers an easy way to feel good about what they are about to eat. The commenters here, however, seem to each have their own different idea. Is it keto? Is it organic/"chemical-free"? Can someone point me to one single definition of "clean" eating that isn't just what you feel is "clean"? If there is, how does it line up with the author's definition? How does the actual definition fit with the content of the article? If there isn't one definition, I'm sort of with the author on this one. "Clean" is whatever labels the consumers use to feel superior through what they are eating.