Hmmm, lots of discussion about traces of syrup etc but no-one has mentioned the effect that alcohol, especially in a spirit like vodka, has on your blood sugars. Yes, your blood sugar will spike but a few hours down the line, your liver will cut off the supply of glucagon to your body potentially causing a hypo. I rarely drink but if I'm on spirits I will drink vodka with normal tonic first then switch to diet. I rarely drink more than 3 but if I did I would have the occasional non-diet one to prevent combining a hypo with a hang over.