sign, symptom, or diagnosis, it is appropriate to assign both the V code and the code describing the reason for the non-routine test. 18
The difference is in the types of non -nutritive sweeteners used. Diet Coke has aspartame while Coke Zero has a mix of aspartame and acesulfame potassium. The beverages have different levels of sweetness and off tastes (I.e. high levels of aspartame have a metallic taste) as a result.
One argument that most people make for diet sodas is that because they lack sugar, the threat of tooth decay is nonexistent. But while sugar plays a large part in cavity formation, it is not the only thing that does. Diet Coke has a pH of 3.39, Diet Dr. Pepper has a pH of 3.41, and Diet Pepsi has a pH of 3.36.