Hi Mel I am on the understanding that they are a no go. Even though it is not real sugar they still make your insulin spike. Allie and Essie are the ones to go into it deeper but as I understand they effect the fat burning. I have tried a sip of slimline tonic and it was really horrible, I could taste the artificial sweetener! We are trying to get our bodies to not crave sweet things and carbs and thus could be a sure way to break all that and start the cravings again. I have found that if I have a few nuts like pistachios with a little Maldon sea salt on them that stops my cravings dead. Hope this has helped?