Technically speaking, on a low-carb diet, you can drink all the diet soda you want. Although you'd have to see how they effect your insulin levels and such, as

Technically speaking, on a low-carb diet, you can drink all the diet soda you want. Although you'd have to see how they effect your insulin levels and such, as some people are effected by it more than others. There's obviously a lot of other potential concerns regarding "artificial sweeteners"... But I'll take my chance with those over sugar.