I have found that there are varying opinions on this topic. Neither coffee nor diet drinks affect my blood sugar level. Many other diabetics say they are affected. There are some, however, who say that caffein and diet cdrinks do raise their blood sugar. The great majority of people who have responded to this question on other diabetes sites say that caffein and diet drinks do NOT affect their blood sugar at all. I drink only one cup of coffee and only one diet soda per day. If I drank several cups of coffee and several diet sodas each day it might be different. I don't know.
Richard
Richard