FINALLY AN ANSWER....

Finally an answer which is worse - regular soda or diet soda? The answer - regular soda.
But this does not mean diet sodas are a good option.
​Depending on the type of artificial sweetener used, they can also cause liver problems. & fat gain.  

https://www.openevidence.com/ask/8faf49f0-b72a-4aa5-bb62-a8a3f4dd0080?eid=&oeid=eYzGxeUgDdAGhLV8k-DhIw