Bolusing for low GI/Slow Digesting Carbs

i know this might seem like a silly question considering how much i generally eat, but i have little experience when it comes to bolusing for foods like lentils, peas, corn, etc.

i know that YDMV, but i was curious to know how you bolus (using an insulin pump) for these types of foods.

please share your methods to give me a general idea of where to start from.

thanks in advance,

Corn is higher carb, peas lower.
Lentils have protein also. (mid carb?)

I would expect corn and peas to hit relatively quick so would do a normal bolus based on carb count.
Lentils slower. Sometimes we have lentil pasta and would use an extended bolus for that.

In addition to using extended for “slow” foods, if the total carb count for the meal gets in the 50+ range then we are going to need an extended bolus regardless.

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I bolus for lentils half up front, half about an hour later.

Peas I don’t even bolus for because my son usually eats so few. Same with corn. But popcorn I just bolus upfront for all the carbs.

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thats interesting, b/c i can bolus 100% upfront for simple high carbs foods. but i do need to pre-bolus for them.

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Even if the total carb count gets very high?
What if simple carbs but something like 80 carbs total for the meal?
Would that still all just be a single upfront bolus?

For that there is no doubt we would plunge low and then ride the roller coaster train for hours later if we did not extend it.

I’ve not tried eating something like 160g dry toast to get 80 “pure” carbs, but in any kind of normal but high-carb meal I usually just prebolus and that’s it. As a smaller example, breakfast yesterday was 64g Bob’s Red Mill old-fashioned muesli (32g carb), about a cup of full-fat milk, about 9 oz blueberries, followed by a pot of tea with 2 Walkers shortbread biscuits. Total carb in the 62 - 67 range. I didn’t wolf it all down in a flash, which might matter. A 10 minute prebolus led to a brief spike to 170 followed by a return to 90 over the next 3 hours. A 20 minute prebolus likely would have held the spike to 150 or less, but yesterday I didn’t feel like waiting that long.

Our differences in bolus technique may be interesting, but fundamentally, a strategy that gives satisfactory results is a good strategy. So in Thomas’s household an extended bolus is the right answer, and in DM’s house (and mine) it’s usually prebolused all up front.

I also wonder if there could be substantial differences in how fast different people digest their food?

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…and in every other factor that ensures YDMV. That’s why we all have to run our own individual experiments to find what works for us rather than just following some simple rules that the doctor could teach us.


i am certain of that. especially with Ds who have diabetic gastropareses.


I bolus similar to @TiaG 's post. A percentage based on simple or fast cabs up front and the balance (larger) to handle fiber /protein /fat 1.5 to. 3 hours later on an extended bolus.

i have never (yet ) bolused for simple carbs above about 65gms, so i cant answer your question. but my high carb meals are usually a mix of carb/protein/fat and then i must do a dual/extended bolus. must must must. (generally its between 2 - 3 hours in duration, depending on the content of the food i.e. pizza, burger and fries, steak, fish, cheese…etc)

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For pizza that many people report as being more difficult, if you only have one slice
Would you find this easy to bolus for but it is only when you go into the 2,3 or 4 slices that the bolus becomes substantially more difficult?

I just often see the amount of food/carbs consumed as impacting the way we need to bolus and more so than the obvious of twice the carbs is twice the insulin. That works for us to a point but once we pass a threshold then we need to start delaying insulin. But I never hear anybody else mention anything like that so it gets me curious.

As well, it is the unusual meal for us that crosses 50 carbs so it is more difficult to see patterns for those things that are done less frequently. So much else is always changing it can be hard to accurately and properly state that X is caused by Y when you know that A, B, C and D are thrown into the mix as well.

Still - there seems to be something there for us.


not certain i completely understand what you mean here. BUT, if i am on the right track, i typically eat 2 slices of old fashioned NYC pizza. not the thin crust crap. the real deal. i go to the same joint every time, so i have learned my formula for what i want to eat.

b/c pizza has sauce (and god only knows whats really in it, i.e. sugars) and a pound of cheese on top of crust (who knows whats in that crust) i have to bolus up front and then extended; so i bolus for 95gms of carbs with a 40/60% split (dual wave bolus) over 2.5 hours. i get a nice flat line in range every time (so far).

this formula took me over a year to nail down :wink: and it was not easy. but, i love pizza so much, it was well worth the trials and errors.

hope this helps.


Not quite.
So what I am wondering is…

And bear with me - I know this is a crazy idea.

Rather than having two slices of pizza with a bolus of 95 carbs split bolus 40%/60% over 2.5 hours, what if you only had ONE slice of pizza (gasp - the horror) (lol) would it simply work out the same with the same end result if you did a bolus of 48 carbs split bolus 40%/60% over 2.5 hours.

Or perhaps a similar idea in the other direction but maybe one which would be more appealing.

What if you had FOUR slices of pizza with a bolus of 190 carbs split bolus 40%/60% over 2.5 hours.

So the basic question: Is the I:C (insulin to carb) ratio really linear.

As we became more advance in our understanding, we learned that the ISF (Insulin Sensitivity Factor) is NOT linear. Perhaps it takes one unit (of insulin) to correct 35 points of BG when in the 120 ~ 160 range however that same unit might only provide a 20 point of BG correction in the 250 ~ 300 range. I believe this is common for many people at least the concept of higher BG requires more insulin for the same number of points correction.

So I just wonder. What else is perhaps non-linear which in our beginning classes we were told otherwise?

And not knocking our initial classes. Everybody must start learning somewhere. Jumping right into the advanced course is IMHO not a great path to success at least for most people myself included. I certainly do better by starting with the basics, learning that and working up into the advanced.


glad that you brought this up. it is deffinitly an interesting concept. i started out my pizza experiment with just 1 slice before i moved it to 1.5 slices (shared second 1/2 slice with my husband) and then i moved up to having 2 slices. i got very enlightening news. for one slice, i think (if i remember correctly) i bolused for 65 gms (40/60% over 2 hours), then i moved up to that second 1/2 slice and i bolused for 75gms over 2 hours. then i bolused the 95 gms spread over 2.5 hours. clearly, not linear. why? have no idea. it was just the way that the cookie crumbled :wink: (no pun intended).

i also want to add something that eric has been telling me for about a year now: “not all carbs are created alike.” i was eating oatmeal every morning before my swimming. i needed a 1:65 / 1:7 ICR to accommodate this meal. this morning i had 3 Jumbo eggs and 2 slices of Rye toast and i changed my ICR to 1:75. after 2 hours, i crashed down to 40. i am planning on eating the exact same Bfast tomorrow morning at the exact same time (hopefully in the same BG target range) and use an ICR of 1:85 and see what happens.

certainly no one told me this info when i was diagnosed :wink:. i didnt even have a pump back then, so there were no ICRs. everything back then was a crap shoot.

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Ah - you sneaked into my scary mental playground and played ahead… Very sneaky…

So, if you had the whole thing working good with one slice and bolusing for 65 carbs then a straight linear I:C would have you eating two slices and bolusing for 130 carbs. However, you said you actually bolus 95 carbs for the two slices. (For the sake of this academic discussion, we will assume your husband is not actually sneaking pizza when you are not looking!!!) So, double the pizza but you only bolus for about 3/4 of the actual carbs.

This is similar to what we were seeing. Significant amounts of carbs require less insulin per carb. I was not sure if it was only us or there was something more to this.

Very interesting that you report similar.


i know for a fact that my husband is not sneaking any of my pizza; i keep a close watch on him at all times whenever food is involved. no one comes near my food. :wink:

i dont know why this is how it is, but it is. this definately would not have worked out this way if we were left to using the old “exchanges” system. (remember those unhelpful directions?) LOL

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Pizza is a delayed bolus for us whether he eats one slice or three. But ours is a toddler. Same goes for burritos.

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Ice cream! How do you bolus for ice cream? I can’t seem to get the hang of it so I just do without. :crying_cat_face:

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i’m not a big fan of ice cream, but i know that the higher the fat content, the slower it will digest, so all ice creams are NOT created equal.

for me, a starting point would be doing a 50/50% dual/extended bolus, of 50% up front and 50% over 2.5 hours. maybe add some extra insulin to account for the fat. just a guess.

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