Dual-Wave Bolusing and High-Fat Meals. Can You Do the Math?

I’ve found that the tastier the food, the harder it is to control my post-meal glucose. My old pal Paradigm 515 helps me by offering a dual wave bolus to try and cover those tasty but slow digesting fatty carbs, but I’m still having some trouble with 4-8 hours post meal spikes, on occasion.

For context, a recent bad-for-me example is as follows: 80g carbs, unknown but high fat meal, 70/30 dual wave bolus over 3 hours. Pre-meal BG 80, 2 hours post-meal BG 79, 4.5 hours post-meal BG 190. Very frustrating.

I’m shamefully unskilled at using the dual-wave option on my pump, and I am wondering if anyone can offer some insight on dealing with these delayed spikes while preventing short term hypos.

To be sure, I’m not looking for an answer that says, “you need to keep your carb counts lower, and try and avoid high fat meals!!!” I’m trying to manage those once and awhile, somewhat unavoidable social binges. I promise to be healthy and low fat/carbs the rest of the time!


Here are a couple thoughts.

  1. Is it possible you are having some delayed stomach emptying from gastroparesis? This can cause some very odd things to happen. I had it as a side effect of a med and the food would sit in my stomach for hours and then suddenly release. So I was seeing highs from carbs many hours after eating them. Gastroparesis is very common among people with longstanding diabetes. It’s another neuropathy (vagus nerve, I believe)

  2. Are you considering your protein input too? Protein can turn into carb in the time frame you are seeing highs.

  3. Pasta doesn’t start to hit the blood stream until 4.5 hours. Are you eating it?

Jenny and Lindsey, I’m pretty confident that its not gastroparesis, for a couple of reasons. First, I’ve only been diabetic since 2004, and I’ve been very well controlled the entire time, but more importantly, second, the late spikes only occur in the presence of high fat meals (regardless of amount of carbs). I’ve pretty reliably narrowed it down to a direct relationship with saturated fat.

Thank you both for the suggestions, I’m going to try spreading out the square-wave over several more hours and see how that works. I’ll let you know how it goes!

Thanks for the great input!

Its funny you mention the basal rate in the evenings… just yesterday I increased my evening basal to cover the trend I was seeing in evening and late night (relative) highs. Unfortunately, this also happens to be the time I am most likely to eat an unhealthy meal (read: higher fat) which can also cause the delayed digestion of the carbs.


I agree with others that it could be a matter of a longer square-wave duration or a need for a higher basal rate in the evenings.

But you should only test one theory at a time, otherwise you won’t know which one had what affect.

So if you’ve already changed your basal rate, keep the same square wave for your next high fat meal and see what the results are. After one or two of those, change the duration of the square wave to see what changes.

I’ve found these rules to work for me when programming the dual-wave option (I also have the 515):
-I assume 3 hours for the spike due to fats and carbs.
-I assume 10% of the value for fats
-40-50% of the value for proteins.

So, if I eat something (a protein shake, for instance), that has 24 grams of protein and 10 grams of carb, I will put in 10 grs (for the carbs) + 12 grans (50% of the 24 grams of protein) = 22 grams, and as the pump to give me about 45% (or as close to it as possible, because that is what 10/22 is) now and the remainder in 3 hours.

Ever since I started applying these rules, as long as I’ve gotten the values of carbs, fats and protein right, I’ve never spiked with high fat/protein meals with the pump.

Hope this helps!

Ah! I found this video I posted “forever” ago here:

High fat will definitely delay digestion too.

For the record, it’s worth noting that High Fat is ONLY “unhealthy” if it is a combination of high fat and high carb. The best numbers I’ve ever had for cholesterol, blood pressure and blood sugar were when I was eating 70% fat and 15% carbs. I can’t eat that way now but it lived up to what the research has found about the healthfulness of a very low carb diet.

As carbs rise, however, fat becomes more dangerous, partly because the high carbs turn into triglycerides after digestion–and also because the high blood sugars they cause will clog up the receptors on the LDL molecules making it difficult for the normal mechanisms that the body uses to remove LDL to function.

There is SO much bad information out there about the healthfulness of fat which derives from the fact that decades of research on “high fat” diets was actually of high carb diets with a lot of fat in them. Since something like 1/3 of the population has pre-diabetic blood sugars, those high carb diets with a lot of fat in them were killers.

But high fat/very low carb is probably the healthiest diet there is for someone with abnormal blood sugar.

Jenny, you’re correct that high fat itself is not a problem, but it is important to make the distinction between saturated and unsaturated fats (as I mentioned in my reply above, noting the correlation between the high sugars and saturated fats).

As I’m sure you know, unsaturated are the good fats – the one’s I’m sure your referring to when you say “fat” – which include the renowned omega-3 and omega-6 fatty acids. A diet higher in these fats is indeed good.

Manny - how did you come up w/ that little algorithm for the dual-wave bolus? Is this something that docs or CDEs tell you upon getting the pump? I’m training tomorrow and have no idea what to expect. My biggest concerns are figuring out what to do square-wave and dual- boluses (boli?) for, how much to give and how long to make them last. I’m just hoping w/ all my might that they will give me some magic formula.


I’ve heard that, but when I was eating very low carb I ate quite a lot of sat fat and saw my cholesterol and triglycerides plummet and my HDL go up near 70.

The data about sat fat are, again, too entwined with the high carb diet they were tested with to be helpful.

Also, it is worth noting that earlier research did NOT distinguish between Sat fat and Trans fat. Much of the bad rap of sat fat may be due to the inclusion of trans fats.

Trans fat is EXTREMELY bad for you. I have avoided eating any for 9 years.

I’m assuming when you say you do a 70/30 dual wave that means you give yourself 70% of your insulin up front and the rest over 3 hours? I was having similar problems and I now do about 30% up front and after I’m done eating schedule the rest for over 4 hours or so. I often find that I need to increase the amount of insulin a bit above what I would normally give myself for that amount of carbs. Honestly, sometimes it just requires a little bit of guesswork and testing after a couple hours but generally it has worked well for me (and I’ve actually found it works better for me just for high carb meals even if they aren’t high fat).

It is true that saturated fats are often found in foods that also high in carbs, but it should be noted that sat fats are mostly animal fats, so things like red meat, and the like are going to be high in this type of fat.

Trans fats are indeed horrible. Trans fats are unsaturated fats that are chemical transformed to become saturated. Its the stuff that makes fast food fries, etc. taste so wonderful (and so deadly!).

Nikki, yeah that’s exactly what I was doing (70% bolus, 30% over 3 hours), and its starting to look like that was part the problem. In the interest of science, and that fact that my girlfriend wasn’t home last night to stop me, I decided to give the recommendations here a whirl with some tasty high carb, high fat goodness with the following results:

*100g carbs / 30-50g fat (estimated from Calorie King)
*Programed in 125g for dual-wave bolus, with 50% up front, 50% over 6 hours (about 11.5U insulin)
*starting BG: 65 mg/dl
*1.5 hours post-meal (9pm): 108 mg/dl
*4 hours post-meal (12am): 176mg/dl (gave an additional 1u bolus)
*7 hours post-meal (3am): 128 mg/dl
*10 hours post-meal (6am): 102mg/dl

I’ve been below 100 mg/dl the rest of the day today!

Looks like there is a little tweaking to do still, could be math error on carb calculation, but it seems that lowering the up front bolus and spreading out the square wave was the key. With the 2hr. post-meal so close to 100, I could probably even drop the bolus down to 35%-40% with better results.

Thank you to everyone for the help! I felt great today even after the bad-for-me meal (in the interest of science, of course).

That’s fabulous! I’m glad you are finding something that works. I remember how excited I was when I figured out how to eat pizza and keep my bloodsugar in a relatively normal range.

I started out doing the 50/50 bolus for 2 hrs after. I was having lows 2 hrs after anyway, and spikes later on. My doctor and I talked about it yesterday and I am going to try a 30/70 for 2 hrs and see if that helps any. I think you just have to play around with it to see what works best for you.