I find it really important for my blood sugar maintenance for me to "eat to my meter." Basically, I'd eat a breakfast, then take my blood sugar reading 2 hours later and see where it was. If it was too high, I knew that whatever I ate had a tendency to "spike" me, and I'd avoid it. Once I found a couple breakfasts that didn't make my BG go too high, I just ate them, and went on to testing after lunch. Slowly, I built a repertoire of foods that I know I can eat that don't spike my BG.
I found that oatmeal spikes me, but a small serving (1/4 cup) of beans doesn't. That regular or wheat bread will, but high-fiber bread won't. That rice will but potatoes won't.
Each person is a little different. Your meter will tell you more than anyone can (even your doctor) about what affects your personal blood sugar.
I highly recommend the following site for information on how to eat to your meter.