Looper Question

I was wondering if there is any way to do what @Eric has suggested to verify your insulin delivery is flowing correctly but when dispersing 5 units it would not show up in your daily usage? I tried a test of .5 units while the pod was still attached. I deleted the entry in both active insulin & insulin delivery but the dose still shows in NS. Any recommendation?

This conversation between @Trying & @TomH got me thinking about features in Loop I had not really taken advantages of.

In this photo you see:

Taco with 30g carbs entered with a 3 hours absorption time set. Loop says 75g Carbs absorbed & 55 minutes time. Is the 75 absorption accurate? Is my carb count that far off? I had 1.5 oz of corn chips bag said 19 carbs for 1 oz. Some chicken with bell peppers I figured 0 carbs. 55 minute absorption time. I am woefully confused :frowning_face:

Oatmeal 55g carbs entered 3 hours time entered. Loop shows 64g absorbed 2h 18m absorption time. K I ate ¼c oatmeal 15g + less than ¼c craisins 30g about .5 tbsp brown sugar 5g that’s 50 not 55 yet Loop says 64g absorbed. I just don’t get it.

Any insight would be appreciated.


Yes, it is my understanding that this indicates that the amount of insulin used was more likely close to what 75g Carbs would need (based on your settings I/C ration, ISF, etc.). It doesn’t necessarily mean that the carb you ate required that much insulin though because there could have been fake carbs, etc., as well as settings may be off for whatever reason for those particular hours. I sometimes enter fake carbs (enter carbs w/ or w/out insulin) just to keep Loop from setting my basal to 0. I only do this if I am pretty certain I am not actually going low though! I know this is not a great idea if one wants to totally rely on the Loop algorithm but sometimes, as I said, my current settings seem to be off. I don’t want to change my settings because mostly they work! I could do an override, but temp basal is more difficult for me to manage than a correction bolus, or maintaining a standard basal.

1 Like

@Trying something is defiantly out of wack with my settings. I am going to try fasting to see if I can 1st get my basal stable & then test ICR & ISF.

Thank you for confirming. Seems this could be happening quite a lot. I see the high that correlated with not having enough IOB. I have to admit I have heard the term “fake carbs” but I don’t really understand it. Read it also on the iAPS / Trio site that Trio does not require the use of fake carbs. Makes me wonder about Trio with UAM & if for me that would be a better system. I understand that it can even be set for “aggressive” to get you back into range faster. That for me might or might not be a good thing. Could just make for a faster roller coaster ride.

Can I ask in your Loop setting Dosing Strategy are you using Temp Basal Only or Automatic Bolus?

I need something that is more aggressive about getting back into range but stops early enough that I don’t get a crashing low.

Thanks for your input :smiley:

I refer to fake carbs when I enter some amount of carbs but I am not actually eating them. I will usually do this when I feel I need a slight correction (and will actually accept the small bolus Loop calculates) or I want Loop to continue to give me my basal (and I won’t accept a calculated bolus) rather than its current 0 basal. Basically fake carbs are trying to prevent a spike but only do this if there is no danger of it causing a low.

Yes, Trio has several additional preferences one can set to more fine tune for UAM, along with its Meal Settings which supports Fat/Protein settings mentioned by @TomH in the iAps thread. I have Trio installed but am still only testing it with a pump simulator, and my Nightscout site as CGM for testing.

I am using Automatic Bolus.

1 Like

I know this is common practice when people do basal testing. But the fasting should be done between normal meals, rather than anything different than your normal regimen.

I mean, if you fast 12 hours to do basal testing, and you don’t normally fast 12 hours, then your basal settings will be set perfectly for periods of 12 hour fasting. And that might not be the same as when you are eating normally!

In general, when we are not eating for extended times, we need less basal then when we have regular meals.

Our bodies adjust.

Less food means we need to conserve our fuel. So we conserve fuel and that means we reduce our basal metabolic rate.

When we ear frequent big meals, our bodies feel free to spit out glucose and insulin to burn all the fuel. Hey we have plenty! Let’s use it!

It’s kind of like how people take more trips when gas prices are cheaper.

So I suggest you keep your fasting focused on short times between meals, and don’t make huge adjustments to your normal routine.

1 Like

I have been doing my fasting kind of in zones. I have understood in the past that in order to test your basal you need to have no IOB & no COB. Is that how you see it?

Much Thanks!


Yes. Doing it in different time segments without food or bolus insulin is the way to go.

The reason I posted is just to make sure you aren’t trying to go an entire day. I have heard some people do that, and it totally changes what their actual requirements are!

1 Like

It does sound like your settings are way off. Your thinking that you should test that your basal is right and then work on insulin:carb and sensitivity is right. And your comment that you want to test the basal by watching when you don’t have IOB and COB is also right. And Eric’s comment about avoiding long fasts is right too. I just skip a meal and watch to see if my BG goes up or down all by itself for no reason. That’s what a good basal setting is supposed to prevent. Then for insulin:carb I watch what happens after I bolus for a meal with very accurate carbs. If the BG goes up and keeps climbing, or goes up and doesn’t come back down, that means I needed more insulin so I’ll adjust the insulin:carb to fix that. On the other hand, if my BG just goes up a little and then starts crashing, that suggests I took too much insulin, so maybe my insulin:carb ratio was too strong.

In the specific case you show, you told Loop you were eating 30g, and it says the insulin they gave for 30g was all used up in 55 minutes, and they kept adding more and more insulin to cover rising BG, and it looked as if you had actually eaten 75g. How could this happen? One way is that you actually did eat 75g of carbs, not the 30 that you thought. Another way it could happen is if your infusion site wasn’t absorbing the insulin properly, like when a pod is tunneling (leaking insulin back out alongside the cannula to the skin surface) rather than the insulin staying in the subcutaneous layer and being absorbed into the bloodstream. A third way it could happen is if your settings are way off, so the insulin dose given for the meal was much less than was needed.


Appreciate your insight. I am a lazy D so I started out with my first segment at night time after dinner & before breakfast. It’s an easy stretch to look at unless Dexcom does not cooperate. Lots of noise, jumps, bumps & calibrates. The D life is an adventure :grin: but it will all work out :smiley:

@bkh Thank you for your explanation & input. For me it’s probably all three of your examples. :wink: if I didn’t have bad luck I would not have any luck at all :joy:

My carb count on my examples I believe to be correct. I want to try what @Eric said about testing the insulin coming out of the cannula on my Omnipod Dash Pod. Having said that though that would only prove the pod is doing what it should. With tunneling would the skin surface be wet if that were happening? I have not noticed any wetness… On absorption is there any way to tell that insulin is being absorbed correctly? <that’s going to be a tough one)


By the test last night through breakfast time fasting I do not see any real problem with my basal rate. Maybe later a little tiny bit of fine tuning. I don’t see any evidence of occlusion or insulin stoppage. Been looking at absorption on line but so far only finding how to improve it. Still considering if when bolusing I am getting tunneling as part of the problem.

1 Like

Sometimes if I touch the skin near the pod cannula and then smell my finger I can smell insulin. The other way is when I remove the pod if I see wetness or dry stains around the cannula area on the underside of the pump. I don’t have wetness on the skin except in case of an extreme site failure.

If I want to be sure, I give an injection by syringe in an area on my chest that has pretty much never been used for insulin infusion before. I trust that much more than any pump infusion, and would use that to rule out any pump dosing/absorbing issues.

The noise and jumps don’t matter for basal testing. Calibrates should be avoided during basal testing because they mean the start point of the graph is not consistent with the end point of the graph (you can take fingersticks if you want, just don’t tell Dexcom about it.). Similarly, run open loop, not closed loop, because otherwise loop will actively try to counteract any basal errors by adding or subtracting insulin to compensate.

The thing to look for in basal testing is whether the BG overall wanders off either higher or lower. If it jumps and climbs and falls but overall is roughly at the same general level a few hours later, that says the basal is fine for that time period.

In your graph, if you were running open loop (so loop wasn’t trying to adjust your BG, it was just giving the scheduled basal) then I’d say the basal was fine, provided the falling BG from 9pm to midnight was the tail end of a meal and bolus, like if dinner was around 7.

1 Like

Thank you :smiley:

Thank you :smiley:

Oh Crud Monkeys :thinking: I was in closed loop…

New Day New Lesson :joy:

Thank you!


Hey, one other mention on the pod occlusion stuff.

It can sometimes take a lot of insulin before it will detect an occlusion. I have tested this out by removing a pod and clamping the canula, and doing boluses. In my tests, it sometimes took up to 4-5 units before it detected an occlusion.

This may not be relevant to what you are doing, but just wanted to mention it.


Good to know. Thanks for thinking of me. :smiley:

1 Like