For the past couple of weeks I've been reevaluating my diabetes status. ...
When I was first diagnosed 5 years ago I was a non-obese with sudden onset and classic symptoms of type 1, including ketoacidosis. After having some antibody tests done and seeing an endo, the initial conclusion was that while I had no indication in the anti-body tests that I was a type 1 (or 1.5 if you prefer), I was probably in a honey moon phase and that, eventually I would show my "true colors". Incidentally, I had completely forgotten this part of the diagnosis until some events (described next) made me look at the original diagnosis from the endo.
About 6 weeks ago I was pretty interested in my fasting insulin levels. I am (now) a runner, and I've read that fasting insulin will be lower in athletes. When I got the results back I was indeed at the low end of the scale: 3 (average normal range 3 -19). So I began some more intense meal time testing, particularly post-prandial, including 1 hr post meal (typically I only did it two hours PP). When I first did it I got a huge 1hr pp spike -- to 210 -- which is really unheard of for me. So, since it was time for my semi-annual check-up, I ordered a slew of blood tests, including anti-islet and c peptide.
Well they came back with me still firmly in the type 2 camp. And why did I have a couple of strange pp glucose spikes? Sweet potatoes. I've traditionally eaten sweet potatoes as an alternative to white potatoes because of higher fiber content and lower GI index rating, but I've found out that for my body, they actually give me a higer spike than regular potatoes, including fries. I tested this fairly rigoursly, over a couple of weeks, including the same amounts of exercise, carb/fat/protein ratios, meds, etc. and consistently the one factor was sweet potatoes. In fact, in attempt to really blow things up, I went out to a traditional wisconsin friday night fish fry, had 4 peices of deep fried cod, clam chowder, coleslaw, french fries, a roll, and ice cream --- a meal tipping over 1000 calories, over 100 grams of carbs---, and my 1 hr pp bg was 165 with a 1000 grams of metformin (on a day with no exercise).
So on another day I tried a relatively low carb dinner (30 grams of carbs, about 400 calories), on a day I ran, added a sweet potato, and again a 1 hr pp of 203. And I never get anywhere near that with much higher carb or calorie meals (although I don't usually have those.
Lesson: diabetes is an idiopathic disease. While there are some broad generalizations, it pays to know what inputs (food, stress, etc.) and outputs (exercise) do for you blood glucose levels.