How to dose insulin for fat with type one diabetes

Lauren Rapaport
Featured Podcast Episode
August 28, 2023

Reader question: "How do you dose for fat? My 7yo daughter is T1D for two years now, and even with a moderately fatty meal (say 10g of fat) we notice a hefty BG rise 1-2hrs postprandial. The more fat, the bigger the rise, and the longer the delay. No one can tell us how much insulin to provide for these rises, or when, so we have to guess. And pumping in insulin without having an idea of how much is needed is not great practice, especially in the overnight hours. We can dose for carbs... How do we dose for fat???"

Risely coaches' answer:
This person hits on such an important (and challenging) thing: there is not a *specific* formula for dosing for fat in the same way that there is for carbs. It takes a little more observing and experimenting. Try not to get frustrated in the process and stay curious!

1. Track what happens with these foods.
Specifically, try logging what your blood sugar is at meal time, 1 hour after, 2 hours after, and 4-6 hours after, along with how much insulin you are giving for the meal and for any corrections following. Remember that fat digests slowly and causes insulin resistance so seeing higher blood sugars hours after the meal is not abnormal.

2. Experiment based on the pattern.
Once you recognize when the rise happens and how high she tends to go, consider getting AHEAD of that (because you know it is a pattern).
Example: if you always shoot up to 250 two hours after eating, experiment with a "buffer dose" for that 250 at the 1.5 hour mark to get ahead of it.
You can also experiment with temp basal increases or extended boluses, depending on your technology.

3. Refine your strategy based on results.
Nailing the exact amount and timing might take several attempts. If you usually go to 250 and on your first experiment you only go to 200, that is a WIN! And it gives you information that you can use to improve in the future.

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