I was told by a doctor that diet soda can cause your blood sugar to drop just like you were using REAL sugar. (GASP) Especially if you have a slightly low blood sugar.
Another thing is that a LOT of people are highly allergic to Aspartame (NutraSweet) I am one of those. It put me in the hospital 2 times and the docs couldn’t figure out what was wrong with me. I haven’t had a diet soda in a year and a half. I had quit for 6 months and tried it again and got sick again, so I knew what the problem was. Different people react to Aspartame in different ways.