I searched for this in the hope of enlightenment regarding diet soda and diet energies because with 2 cans a day I'm a high consumer and wanted to know my risks.
The 3 biggest concerns I found for me after doing a little research:
- An up to 3x times higher risk of ischemic strokes for those drinking more then 2 cans a day BUT already "adjusted" for "unhealthy" blood markers, BMI and diabetes etc. (doi:10.1161/STROKEAHA.116.016027 and doi:10.1161/STROKEAHA.118.023100)
- Artificial sweeteners have shown to change the gut microbiome in rats, in a way that "some" might have a higher ratio of bacteria that are transforming food into energy more efficiently.
- Artificial sweeteners Aspartame and Stevia have shown a higher insulinogenic index 120 min post lunch, so that might increase the risk of insulin resistanc and type 2 diabetes. (doi:10.1016/j.appet.2010.03.009)