Looking to build an App - Extended Bolus Assistant

I’ve been T1D for 19y, and on a pump for over 10y, and I’ve always had challenges with fatty foods…

  • Initially, I was taught to count Carbs + 1/2 Fats for Bolus, and do a correction about 2h after. for 1/2 Fats.
  • Once on a Pump, I was taught slightly differently, but basically, Dual wave for fatty foods, and extended Square wave for very fatty foods, or log GI foods like basmati rice.

Over time, I found some methods that worked for me, and I found that protein content made a difference. So I had a spreadsheet setup to plug in my numbers, and have it tell me what pattern to use. My Rudimentary sheet does the following:

  • takes 5 inputs: Carbs, Fiber, Fat, Protein, I:C Ratio (As a decimal)
  • provides output as: Total Carbs, CarbEQ (For Fat+Protien equivalent carbs), FPU, Extend Hrs., Initial Bolus, and Extended Bolus (Both as %; and Units rounded to 0.1)

A few weeks back, I learned about the Warsaw Method and thought Wow… this is great… and it has well documented research behind it, and not far off from how I was doing things.

Now, I’m wondering how much interest there would be to develop such an App to do what I was doing with my spreadsheet.

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@Al.S i followed a similar path about 18 months ago after reading a couple of articles on fat, protein, and FPUs. Your sheet has a bit more than what I developed. In fact, I pulled mine out last night: I wanted a piece of a cheesecake my wife made and it sent me high for several hours two nights ago due to fat content and I didn’t want a repeat performance. The lady that runs the Waltzing The Dragon website talked with Scott Benner on JuiceBox about her FPU calculations. I believe you’ll find a couple of apps for iOS and Android already exist, though they probably don’t use the same formulas you do. There’s a lot of different opinions on whether to include and what % of fiber, fat, protein, depending on how much carb is in the mix, and over how long a period, etc. It would be nice if an app allowed the user to set the percentages used of each component and time period that works for them. If you’ve got the programming skills, I’d bet there would be no shortage of input from th folks here on FUD!


@Al.S Here’s a link to a WTD website article Tame Post-Meal Spikes: Fat & Protein - Waltzing The Dragon Inc. also to Juicebox podcast #471 Bolusing Insulin for Fat — JUICEBOX PODCAST. As indicated earlier, it indicates she found the protein (unless its a very high protein content) with some carbs not to be significant factor for her son (many agree with this, including Scheiner from IDS; but some do not), so she discounts protein most of the time. At the bottom of the WTD link has a simplified formula.


I’m an Android user, and was not really able to find any apps to help…

I did have a link to Omni Calculator Warsaw Method page, but thee were more features I wanted than it provided.

A note on why I personally take fiber into account. I find foods where fiber is about 15% i do better with with dual wave. As a general rule here’s what I do:

  • My Carbs are always calculated to exclude the Fiber. - (FiberFree Carbs - FFCarb below)
  • Based on the % of carbs that the Fiber represents, I calculate how long my 2nd wave is.
    • 10%,I set to 1h
    • 15% I set to 2h
    • 20% I set to 3h
    • 25%+ I set to 4h.
  • My bolus/Dual wave ratio is set so from the FFCarb, where I subtract 1.5xFiber from FFCarb (to a max of 50% of carbs), What remains is Initial bolus. and the remainder is the Extended bolus. The max
  • Having a dish with 100g Carbs, and 3g Fiber - since Fiber is < 10%, no adjustment
  • Having a dish with 100g Carbs, and 16g fiber - (so 16% Fiber) I do as follows:
    • Calculate 84g Total carbs. Dual wave of 60g Initial, and 24g over 2h (>15%) or 71% / 29%
  • Having a dish with 100g Carbs, and 30g fiber - (So 30% fiber) I do as follows:
    • Calculate 70g Total Carbs, and since 1.5xFiber is 45g, we reduce it to 50% of the Calculated carbs. Thus 35g Initial, and 35g extended - or 50% / 50%

Adding Fat/Protein calculation to the mix becomes an art…
still trying to figure that properly now that I know of Warsaw Method.

@TomH , Thanks that WTD post was what put Warsaw Method on my radar in the first place. One of the nurses I deal with knows the family. I need check Juicbox podast. something new I discovered. My method was mostly simplified formula, but I found that high protein meals needed more additional adjustment for me

My own estimation was to use 0.75FAT + 0.25PROTIEN. and % of Total carbs that represented for length of Extended bolus. If calculated F+P was < 10%, 1h, 2h up to 20%, 3h up to 30%, and 4h for 40%+ – If actual carbs were < 25%, I would do a split. 60% total extended over 4h, and a second bolus at 4h mark for remaining 40% over 4h. (Obviously checking blood sugars, and adjusting if required).

@Al.S You’ve obviously gone way further than anything I’ve tried and are more meticulous, but if it works, that’s what counts (no pun intended). I’m wary of following the Warsaw method too strictly due to several reports and cautions regarding severe hypo’s by people using it. Your fat and protein % are higher than most I’ve seen, but again use what works. I’ve found 10% protein and 25-50% fat work for me and the time factor is very dependent on overall meal contents, i.e. standard carb count (30-45) w/mixed carb/protein/fat, no need; low carb high fat or protein the more it’s necessary.

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