Basal is basal so if you have it dialed in correctly, you should never be going low from it. It sounds like you may need to do some basal testing to make sure you have the right amount dialed in! If it’s not basal, then it can only be bolus insulin that’s bringing you low…I recommend testing I:C and testing different strategies for bolusing for breakfast meals. Most people spike like crazy if they’re eating carbs for breakfast, so experiement with different dosing strategies…25% up front and 75% over an hour and that kind of thing. But basal and bolus testing are critical to correctly dosing!
If you are dropping low without having eaten first and you’re truly only using basal, then it sounds to me like you have an incorrect basal rate going OR you’re still in the honeymoon phase, and producing insulin outside of your normal basal rate.
When my son, who is 5, eats 25 carbs, we bolus him 1.25 units to give you some perspective. But timing (when you deliver the bolus), what’s being eaten for breakfast, and factors like what your BG is before eating and the trajectory it’s on are all variables to how your BG is going to react after eating.
My first suggestion is: is it possible that you did not take enough samples of what happens when you skip breakfast? Could it be that, if you do it a few more times, you will find out that you need to reduce your basal earlier?
If this is not the case, my second question would be: when you stretch your ICR to 1:25-30, to you get a postprandial peak? If not, I would stretch it further if needed.
If the two suggestions above don’t apply, then I would suggest lowering a temp basal by .15 or so between breakfast and 11, every time you have breakfast.
Basal testing: when we (YDMV though) stay without food for a long time, two things tend to happen for us:
We tend to get liver releases of glucose after regular meal times, but only for some meals
Or (the opposite…) we see decreased basal need. For us that happens after a very early dinner and if we skip breakfast. In the morning we will see a BG trending low.
FYI, my son, when he overdoses for a meal, can run low 4 or even 5 hours later due to bolus IOB. I would not be surprised to see you run low after 3-4 hours.
Yet it is strange to see you run low with an ICR of 1:30 :-). That said, for the past week my son has been running at +50% from 8:00am to 8:00pm for no reason: we try to roll with the punches when we don’t understand.
So that sounds like your basal is pretty close to right. How long does it take to rise 20 points? I think the standard basal test will recommend a small change if there is a 30 point change in either direction over 3 or 4 hours.
Could it be you are bolusing too much for the type of food. Does it have a high glycemic index which would cause the food to be metabolized more quickly? This could cause the bolus to peak after the food is digested. You could add some fat to your meal to help delay the digestion. For me, I recently noticed that if I add whipped, heavy cream to my coffee, my breakfast BG rise will be gradual, spread out over several hours.