two weeks ago someting wierd happened. My husband(the diabetic) came in from outside and was cold. He drank a cup of black coffee to warm up and knowing that coffee has 0 calories he then took his blood sugar. Through the roof!!!!!!! couldn't figure it out, took it again, same result, took mine (non-diabetic) perfectly normal. mulled it around for a while and went on line and googled blood sugar+caffiene. There have been recent studies indicating caffiene can increase insulin resistance by up to 257%. Switched to decaf and his readings have been in the optimal range ever since. Go figure! thought that this was important enough to share.