1 OPINION. 2  The screening process for Syrian refugees is much more rigorous than for other visitors coming to the U.S. (AP Photo/Hassan Ammar)
About 250 milligrams of caffeine â or the equivalent of 2 to 2 1/2 cups (473 to 591 milliliters) of plain, brewed coffee â a day may cause this effect. If you have type 2 diabetes and you're struggling to control your blood sugar levels, limiting the amount of caffeine in your diet may provide a benefit.
Upswing: Caffeine. Your blood sugar can rise after you have coffee -- even black coffee with no calories -- thanks to the caffeine. The same goes for black tea, green tea, and energy drinks. Each person with diabetes reacts to foods and drinks differently, so it's best to keep track of your own responses.