There aren't only two main reasons for anything when it comes to diabetes. If there's one attribute which can be said to characterize diabetes more than any other it would be, in my opinion, complexity . There are at least a dozen main reasons for high fasting readings in my body. There are at least a dozen in your body and some of them are probably different from whatever's going on in me. In addition to the dawn phenomenon (whose cause is as yet unclear to medical science) and gastroparesis, there is also the process of gluconeogenesis to consider. And, as Dr. Bernstein puts it in his book:

"Although the mechanics of the dawn phenomenon aren't yet entirely clear, research suggests that the liver deactivates more circulating insulin during the early morning hours. It doesn't matter whether you made the insulin yourself or injected it; the liver has no preference. " - Text, p. 84.

Then there are also the following to consider: adrenaline surges due to stress, infection and medications for other conditions. The "Chinese Restaurant" effect may also come into play.

That's seven variables right there. I'm sure Dr. B. could come up with about a dozen more right off the top of his head.

I've always gotten into the most trouble with my blood sugars when I begin to think that the mechanisms and the solutions are simple. They're not. They're extraordinarily complex.