Is lasagna forbidden for diabetes. ate small to medium piece 4pm then at 10:30pm ate small sandwich to take my medicine. at 10 am my glucose level 191. so if at the second day my level is high,does this means that it was more high at afternoon &night?

No food is truly forbidden for diabetic patient if you only eat a small amount. The glucose level in the afternoon will depend somewhat on what medication you are taking at night and the next morning. Yes, if the glycemia of 191 at 10AM without breakfast and hypoglycemic agent(s) in AM so your glycemia will be likely higher in the afternoon after lunch time and at night after the dinner.