as far as i know, coffee contains no calories of any sort. energy from coffee is derived from the drink's effect on the adrenal gland, which results in the mobilisation of stored glucose already in the body, ie. energy isderived intrinsically rather than extrinsically. it only CONTAINS calories if you add milk and sugar. too much coffee isn't a good idea at any time but i can't see why moderate amounts will bad on the atkins diet. just bear this is mind though. caffeine will speed up the body's metabloic rate, meaning one burns calories quicker, but it does result in blood sugar levels being lowered in the long run, leaving you feeling hungry again. i dunno how this applies to the atkins diet exactly, but i thought it worth bearing in mind.