<<Disclaimer: Verify this information before applying it to your situation.>> Thanks for the many Emails saying diet Coke IS gluten free. Many, many people have called the manufacturer on this one. I also received many, many warnings about aspartame, an ingredient in diet Coke. Thanks. ***According to the coke company, they are both gluten free. I recently had to quit diet coke because I seemed to be having gluten type reactions from drinking it. I did a survey on my web site about it one time and about 6 out of 10 individuals stated it also made them sick. Again the company states it is gluten free, but I often wonder if maybe there may be some trace amounts of gluten in the Carmel coloring. ****Diet Coke is GF, but it could still bother you for other reasons. I *LOVE* diet Coke, cannot drink it because I have acid reflux, and it's forbidden on the GERD diet. GERD is commonly found in people with celiac.