(1) Animal bodies are dirty. Therefore, animals are inherently dirty. Therefore meat, being the meat of animals and of their animal bodies, is inherently dirty. Therefore, a clean diet is a vegetarian diet.
(2) Junk food is dirty, because it literally contains the same nutritional value as eating an equivalent amount of dirt. So, a clean diet is one in which no junk food is eaten. And the test for whether something qualifies as "junk food" is: What nutrition do I gain from eating this that I would not gain from eating a pile of dirt?
All junk food is unclean and should never be eaten. However, soda is not junk food. All junk food is dirt, but soda has been misclassified as a type of junk food, when soda is a legitimate form of clean food.
