Hi Sarah
I must admit i have never tested for this but lots of people on the forum have a similar reaction, the general concensus is that when you wake and your body is running on "empty" as it were because you haven't had food yet then your liver will dump some glucose into your blood stream in preparation for the days work, try having a breakfast as soon as you can when you wake, this can top up your fuel tank and let your body use the food for energy
just a personal opinion, but i find i function much better if I have my breakfast as soon as i can after i wake
give it a try and let us know
Crofty