Why is caffeine unacceptable in the Atkins Nutritional Approach?
Excess caffeine can drop blood sugar levels and leave you craving sweets. If you’re addicted to caffeine, you must give it up. The best way to do this is to segue from the high-octane stuff to decaf by gradually adding decaf to your full-force brew until you are drinking straight decaf, which you can enjoy with cream. Water-processed decaf is preferable because it does not use chemicals, as other decaffeinating processes do. (Taken from Atkins.