Had breakfast at about 10:30 of 2 sausages 2 bacon 1 egg 1 grilled tomato and a serving of mushrooms. I had a large mocha about hour and half later other than that I have only had tea (drink) but I have gone from 5.2 at 16:30 to 5.9 at 20:00 :?
If you have had nothing to eat since 10:30 then your liver will be producing glucose in order to keep your energy needs supplied. The glucose is stored in your blood and is why your blood sugar level is rising.