Hey Richard,   And coffee is one of them! Not all things with caffeine do this, but coffee is one of them because it is obviously a stimulant and research has shown a few ideas about why it commonly raises blood sugar, but the most concluded theory is:   It decreases insulin sensitivity: http://www.drmirkin.com/diabetes/9897.html http://www.cbsnews.com/stories/2008/01/29/health/webmd/main3763964.shtml       Some people don't have a problem with this, others do. If you want to keep drinking coffee, by all means go ahead and take a little insulin with it! But of course, test often at first to determine the true right dose.   -Ginger