Caffeine/coffee most DEFINITELY causes a high rise in my BG. I now drink decaf, but not often. I've gotten used to drinking water these days and I prefer it. But on the occasion that I will drink coffee I like Luzianne Decaf with chickory. It has a VERY bold taste and is not at all 'wimpy' like most other decafs. The only drawback is it's very hard to find.