Caffeine is supposed to raise your blood sugar. I read this in “Think Like a Pancreas” by Gary Scheiner, and since then I’ve been careful to limit myself to one cup of coffee or one Diet Coke a day.
This is what the book says: "A natural stimulant, caffeine tends to cause a rise in blood sugar levels approximately 1 hour after ingestion. It does this by stimulating the secretion of stress hormones and promoting the breakdown of fat (rather than sugar) for energy. Granted, the amount of caffeine founds in most foods is insignificant. However, consumption of large amounts of caffeine at one time can produce a noticable blood sugar rise. Below is a list of some of the major sources of caffeine:
Stay-awake pills: 100-200 mg
Brewed coffee (8 oz): 100-120 mg
Espresso: 100 mg
Instant coffee (8 oz): 60-80 mg
Tea (8 oz): 30-50 mg
Cola (12 oz): 30-45 mg
Cold tablets: 30 mg
Chocolate bar: 20-30 mg
Chocolate milk (12 oz): 10 mg
This is on page 154 of his book. He then goes on to explain how you can adjust for the rise in blood sugar caused by caffeine consumption.
According to this chart, if you’re drinking 3-6 cups of brewed coffee every morning, that’s between 300-720 mg of caffeine, which is an awful lot. But, you know your diabetes. If you really don’t notice an impact on your sugar, maybe it doesn’t affect you. Or maybe you get some mid-morning or lunch time highs that you’ve never quite understood, and caffeine is the culprit.