Actually in DANDR, Dr. Atkins does mention that artificial sweeteners CAN cause a spike in insulin release that you may not want. The trick to keeping it under control... for every serving of sweetener you have, count it as 1 carb into your carb count for the day. It keeps you at a much lower risk of stalling and undermining what you're working for. If you do stall, try to cut out sweeteners for a couple days to see if it jumpstarts anything.