Dosing insulin is complicated. It is a unique combination of science and art. If you pay attention, write stuff down, and willingly experiment, you will shorten your path to proficiency.
In my experience (not universal!), things like whole wheat bread, brown rice and sweet potatoes spike my blood sugar. Some people can refine their dose size and timing to reduce or even eliminate the spike but that’s a game that I choose not to play.
Dr. Bernstein, himself a long-term T1D, has written about his law of small numbers. This law essentially says that fewer carbs leads to smaller insulin doses and smaller mistakes. Mistakes are inevitable – smaller ones are easier to deal with than larger ones.
Insulin dosing, as I’ve stated before, is a combination of science and art. Your 1:15 insulin to carb ratio is definitely not a set-it-and-forget-it ratio. In fact it’s likely that your daughter’s I:C ratio changes during the day as well as from day to day.
Diabetes is a dynamic disease. The body’s sensitivity to insulin changes – it is not static like the precise ratios that you’ve been given suggest. This is why, especially in the beginning that you record what you do and be willing to safely experiment. These experiments are what will educate you about the unique metabolism in your daughter.
So, there are a lot of moving pieces in this puzzle and your medical team is likely deliberately moving slowly to make changes. Her basal insulin dose size could be the main reason for the meal spiking.
Basal insulin is intended to metabolize the pulsed glucose drip coming out of her liver, nothing more, nothing less. It is a separate job from the meal insulin.
There are protocols called “basal tests” that help to discover the optimal basal dose. Here’s one basal testing protocol from Integrated Diabetes Services. IDS was founded by Gary Scheiner, author, T1D and certified diabetes educator. He wrote Think Like a Pancreas, a book I highly recommend you put on your reading list. I have no financial or otherwise connection to Gary Scheiner and IDS except as a satisfied customer and reader of his books.
I know you look to your doctors for guidance and you should. Over time, you will come to depend more and more on your perspective. This is natural and I believe, preferable. Some people continue to depend solely on their doctor’s advice and I understand that.
But the ideal situation is when the the person themself (in your case, the responsible parent) attains PhD level understanding of one unique glucose metabolism – your daughter’s.
Be aware that my take on this is not without controversy and you should move slowly and carefully if you choose to take on this role. Careful observation, good record-keeping, and persistent experimentation are the keys to success.
You still need the doctors and incorporating their guidance into your treatment plan is the challenge you face.
I apologize if I’m dumping way too much info on you in a short time! Learn a little every day and you will soak all this up in due time. Feeling overwhelmed at this stage is normal and this time will pass.