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The Art of the Pre-Bolus.

"Fucking frost on my eggplants."  Batman tries to wait patiently for his bolus to kick in.“So it’s a Wednesday night … what’s the chance we might not be seated right away?”

“Are you talking to me?” Chris asked, pulling the car into a parking spot near the entrance of the restaurant.

“Yeah.  Sort of.  I’m trying to decide if I should bolus now, because I’m 200 and I don’t want to be high all night.  Or eat ice for dinner,” I responded.

The science of a pre-bolus makes sense to me.  Take your insulin before you eat so that it’s active in your system when the food hits.  Or, in smarty-pants terms:  “A bolus of rapid-acting insulin 20 min prior to a meal results in significantly better postprandial glucose control than when the meal insulin bolus is given just prior to the meal or 20 min after meal initiation,” states the conclusion of this study from 2010 examining the influence of timing pre-meal boluses on post-prandial blood sugars.

I put this theory into practical application during the second and third trimesters of my pregnancy, when insulin resistance was constantly on the climb, as were my actual insulin needs (thank you, hard-working placenta).  Around the 22 week mark, I needed to pre-bolus approximately 25 minutes before a meal.  Around the 30 week mark, I was upping that time frame to 45 minutes prior to eating.  And now, without a baby on board, I still try to bolus at least 20 minutes before I eat.

Making the decision to pre-bolus is a precarious one, because the success of that decision rests in the quiet of variables.  (What, too esoteric?  I wrote that sentence from a cloud.)  Pre-bolusing only works when nothing else gets in the way of eating.

Exhibit A:

Yesterday morning, I woke up to a shiny 218 mg/dL on my glucose meter, so I wanted to make sure I pre-bolused for breakfast, since morning highs tend to stick with me well into the early afternoon.  (Little jerkfaces.)  I took my correction bolus and my meal bolus in combination with one another for my meal (eggs, avocado, and a slice of toast do not judge me for eating toast), and set about playing with Birdzone until it was time for breakfast.  Only the best laid plans of this PWD were derailed by a phone call, a frantic search for Carrots (Birdy’s stuffed rabbit, who happened to be in the dryer, a la Knuffle Bunny), and falling down the email vortex for a spell.  End result?  I skipped the toast and ended up chugging some juice with my breakfast.

Exhibit B:

Before dinner out at a restaurant, I decided not to pre-bolus in the car, assuming it would be some time before we were seated.  But (of course), we were seated and eating within 20 minutes of arriving.  Even though my blood sugar was in range when I sat down, I had a post-meal spike that looked like a rocket ship taking off.

Timing is only part of the art of the pre-bolus.  For people dealing with gastroparesis, trying to predict the absorption of insulin and food is tricky.  For kids with diabetes, the art is more Pollock-y, because who knows what a kid will eat/won’t eat/might lick and then hide in a plant?  The blood sugar number you’re starting from makes a difference (or at least for me), too.  I’ve found that if I’m high, I need to wait until I see a downward slope on my Dexcom graph before I can start eating; otherwise, I start high and end up higher.  And the time of day matters for me, too.  A breakfast pre-bolus definitely needs more time to kick in than a dinner one.

Pre-bolusing, for all of its variables, is one of the most useful things I’ve done to help lower my A1C.  Keeping my post-prandials lower helps my overall control, and every time I see my endo, she nods in agreement when I mention pre-bolusing.  (She also warns me about lows every time, because she’s a doctor and also extremely smart and always has cool sneakers on /digression)

Do you pre-bolus? 


34 Comments Post a comment
  1. I used to pre-bolus, back in my days of taking shots, and then well into the days of being on the pump pre-pregnancy. I had a couple of scary lows happen because of it (like stupid restaurants not seating us and getting us food fast enough, or that work phone call making you go off on a tangent. Been there!!) Then pregnancy changed SO much about how I had to deal with my diabetes. I don’t know if it permanently changed how fast I digest things, or if I have some form of gastroparesis, but nowadays I rarely pre-bolus, but I ALWAYS dual-wave and square-wave boluses. And that seems to somehow do the trick! My post-prandial blood sugars are better than they have ever been. Only the occasional hiccup with them if I eat chinese food or pizza = known evils.

    02/4/14; 11:09 am
  2. I’ve always tried to do a bit of prebolusing, but now since I’m pregnant I find it so important. I’m really interested to read that as your insulin resistance amped up, so did the need for more time in that prebolus. I’ll be keeping that in mind as I wait for that hammer to fall.

    I really do think that by dosing ahead (I aim for 15 minutes at every meal), I’m keeping my spikes less spiky and my baby healthier overall. It’s not always possible, but I do my best.

    02/4/14; 11:11 am
  3. I’m actually bad at pre-bolusing. I definitely bolus before I eat but a lot of times it’s not much before. And while sometimes that turns out ok, other times not so much especially if there are carbs involved. I am trying to work on being better at it. I find it much easier to do at home while I’m preparing food but like you mentioned, it scares me sometimes to do it at a restaurant. For some reason, even though I know for a fact the insulin doesn’t start working immediately, it worries me to be sitting around for 10-15 minutes while my bolus is brewing!

    02/4/14; 11:19 am
  4. Pre-dexcom, I often checked my BG as I sat down to a meal, making pre-bolusing next to impossible. But wearing a CGM makes a giant difference in general blood sugar awareness, so I’ve been trying to pre-bolus more regularly and it definitely makes a difference to those post meal spikes. Occasionally though, I get burned when an apparently stable BG starts dropping as soon as I bolus and I end up low before I start eating. Makes the pre-bolus harder to do the next time round!

    02/4/14; 11:21 am
  5. Always except not.

    I guess I always think of it. Except not.

    But I always test except for when I don’t.

    So here’s how it plays out for me: If I test before hand, and my blood sugar is above 6 (108) then yes I do..around 20 minutes. If it is above 8(144) then I try around 30-45 mins. If it’s above 12 (216) then I would Add an extra correction and bolus 45 mins before hand.

    But sometimes I just want to eat and deal with it, which I do. Except when I don’t.


    02/4/14; 11:26 am
    • Ali #

      “Always except not”. This has to be one of the most perfect descriptions of my style of diabetes management! Love it. Also nice to see results in mmol/L – always trying to mentally convert when reading blogs 🙂

      02/4/14; 11:53 pm
  6. Kim #

    I try to with varying success.

    As a minimum I bolus during, or once my plate is immediately in front of me. I can count on one hand the occasions where it has been after I’ve finishe

    02/4/14; 11:48 am
  7. I love the Batman pictures.

    That is all.

    02/4/14; 12:11 pm
  8. Katie S. #

    Do you feel my judging stare over that piece of toast??? If so, good–because I’m wondering how you only eat ONE piece of toast!

    I’ve been learning to pre-bolus. Eons ago, I got into the horrible habit of not bolusing until after I ate so that I could think about how many carbs I had actually consumed instead of guessing beforehand. (Don’t try this at home kids–it’s a bad idea). I now always bolus before I eat and have been working on trying to do it 10-15 minutes early but I don’t always remember.

    02/4/14; 1:10 pm
  9. beth #

    I REALLY like my pump for prebolusing – it just makes it a bit easier than injections i think if you are eating out or there is a lunch event at work or at someones house – I prebolus an underestimate of what I think I am likely to get, and then top it up when food appears – that would be 2 needles on injections but not with my pump 🙂

    02/4/14; 1:15 pm
  10. I should, but in general I don’t (unless I’m really high going into the meal) — all the “what ifs” scare me. But I do Super-Bolus often… kinda gives me a chance to catch-up on a missed pre-bolus.

    02/4/14; 1:33 pm
  11. Jen #

    In the scenario you described (Wed night restaurant), I would likely have taken the correction dose immediately, but waited until I ordered for the meal bolus.

    Or, it’s possible I would have taken the correction dose and then intended to take the meal bolus when I ordered, but gotten too busy figuring out which beer would pair best with my meal and not remembered to bolus until the meal was over.

    In theory, that could happen.

    02/4/14; 2:05 pm
  12. I pre-bolus almost all the time. If I’m eating out, I usually wait until I order, then bolus (’cause that’s when I really know what I’m eating). I’ve been burned a few times, but like you said, the pre-bolus is great for reducing the post-prandial spikes (as always, this is not medical advice– YDMV).

    02/4/14; 2:16 pm
  13. Sheri #

    I’ve been pre-blousing since I got a CGM because I realized that 100 at breakfast and 120 at lunch was contaminated with a 250 in between. after. every. meal. Pre-blousing for 30 minutes before I eat when my blood sugar isn’t high does the trick. My highs like to hang around, so it’s often an hour or more (if eating at home) before I can eat in those situations. Although it embodies PIA, the benefits are worth it. I dropped my A1c a full percentage point.

    02/4/14; 2:22 pm
  14. Yup, I almost always pre-bolus. Yup, I have also pre-bolused and then gotten distracted and forgotten to eat breakfast until my CGM blares out a low alarm. Grrrrr. Dinner is easier because it usually takes a while to cook, so I bolus when I know the food will be ready in about 25 minutes.

    Pre-bolusing definitely feels more dicey to me when eating out. Usually I wait until we order. Or there is (emergency) bread on the table. And if it’s breakfast and Pete has ordered orange juice I don’t worry one bit about the pre-bolus!! 🙂

    02/4/14; 2:25 pm
  15. Totally worthless when it comes to pre-bolusing, even though it ALWAYS crosses my mind and I made the lazy choice to just not do it. Especially when it comes to those unpredictable situations like going out to eat. When I do pre-bolus, there’s usually interference and it never works out as I’d planned. Sure, it’s self-defeating behavior. But sadly, sometimes there’s more comfort in knowing that I will go high (within reason) and can just correct. My former endo and I got into an argument about this a few times, and I can now feel her scolding eyes piercing my soul as I write this…

    02/4/14; 3:13 pm
  16. I suppose it depends… I almost always pre-bolus my correction dose, even if I’m not sure what I’m going to eat. When I go out to eat, I usually will bolus for my food when I order it, which usually gives me a 10-15 minute head start. Not awesome, but not as bad as waiting until I’ve finished eating! When I eat at home, I’m pretty bad mostly because I don’t always know when Erik will be finished cooking, so I usually will just bolus as I sit down to eat. But more often than not, I’ve tested well in advance and so the correction is at least working.

    02/4/14; 3:59 pm
  17. Christine #

    This and Wil’s article has been great insight. I will give this a whirl at the Luau. Another interesting topic might be insulin resistance. If I travel sitting for a long time, my BG tends to elevate. And I battle to bring it down. Oh, this adventure sure is a learning experience.
    Thanks again for all the comments.

    02/4/14; 4:03 pm
  18. I prebolus my child, and have NEVER YET done it far enough in advance that he has tanked. 15 minutes, 20 minutes, 30 minutes…all fine. I am kind of afraid to do it more than 30 minutes in advance, because that just seems too futuristic.

    02/4/14; 5:47 pm
    • I was nervous, until I was pregnant and HAD to do it that way. Since, I’m less afraid, but still wary.

      02/5/14; 9:50 am
  19. Dennis #

    Thanks Kerri, I needed this reminder and encouragement to resume pre-bolus; when I was taking shots [before I started pumping nine years ago] I would occasionally do this. Now I wait until the meal is server to count carbs and enter that into my bolus wizard. When eating in a restaurant, I always start eating [taste stuff] before the bolus. Many postprandial highs because [my somewhat educated guess and calculations] my Novolog peak is not as soon as it formerly was.

    I won’t criticize your toast for breakfast; almost without fail I have both OJ [6 oz. / 20g] and an English muffin [36g] usually with cottage cheese or eggs for protein. I’ve been eating like that for the 57 years that I’ve lived on insulin; okay, HB A1c is 6.4 for blood drawn on January 2nd.

    02/4/14; 7:39 pm
  20. Emily #

    Of course it depends on a dozen (x a million) factors. But what helps me, when I do, is set an alarm on my phone after the bolus. So, while it’s easy to forget to pre bolus (and I often do) and some times even forget to bolus until after I eat (yes the, “wow I can actually forget I have this disease after 20 years” shamefully proud moment), it is harder to get low (but only if you remember the alarm and then actually eat once it goes off).

    02/4/14; 8:52 pm
  21. Sarah #

    pre-bolusing: 18 years T1D and still scares the sh!t outta me.
    I’ve found dual-wave bolusing a MUCH more satisfactory solution to this and my post-prands’ are still a wee bit higher than I’d like but my deviation is WAY WAY better.

    02/5/14; 12:56 pm
  22. Shana #

    I started pre-bolusing when I started using a sensor about three years ago and could see the crazy post-meal spikes with my own two eyes. I even have my husband trained, which is good because he’s the cook (“Dinner will be ready in about 20 minutes and we’re having sweet potatoes, so you might want to shoot now” – it’s amazing). I’m especially nuts about it now that I’m pregnant, and I have some kind of ridiculously elaborate rituals – like, for breakfast I usually chop up a piece of fruit and put it in yogurt with a little bit of honey. I’ll bolus, chop up the fruit, eat about 1/3 of the fruit, then go shower and get myself ready for the day, and then 45 minutes later I’ll come back and eat the rest of the fruit with yogurt and honey. But you’re right that it depends on so, so many variables, most of which you can’t control and some of which are completely unpredictable! I do use the timer on my phone too – that helps a lot. But I hit low a lot too. I wish it was easier/more socially acceptable to be more demanding about knowing eating menus and times. Like when friends invite us over for dinner, as soon as I show up I wish I could ask what they’re serving and how long it will be til they serve it, but that just feels rude!

    02/5/14; 1:19 pm
  23. I try my absolute hardest to prebolus. I have to bolus at 30 minutes before lunch otherwise the whole afternoon is a mess. That’s tricky when you’re stuck in a meeting and headed low, but STILL have to get active insulin in there.

    Whenever we go to a restaurant, as long as I’m not low, I’ll bolus for 20-30 grams of carbs then add the rest after I’ve ordered. I’ve gotten my morning routine down to a science on the workdays that I put on my pants, bolus finish gathering my things and I”m drinking my breakfast when I’m halfway to work. Weekends make everything go to crap though.

    02/5/14; 2:21 pm
  24. Nell #

    Since I’m in a hurry to get breakfast, shower and get to work, I bolus only 10 minutes ahead of my usually small meal. Lunch requires a 30 minute pre-bolus. For dinner at home I bolus 20 minutes ahead of eating. But eating out is a crap shoot no matter what I do. Usually I bolus as soon as I order, and if we decide to share a dessert, then I bolus for it when it’s ordered.

    02/5/14; 8:24 pm
  25. Karen #

    Thanks for the reminder to do this! I’ve done it from time to time with good results. I’m now nearing the end of my second trimester of my second pregnancy and I’m starting to see the BGs swing upwards again. Remembering to pre-bolus today, after reading the post last night, awarded me a pretty day on my Dexcom. Yay!

    02/5/14; 8:40 pm
  26. Yes….if I remember to. I have a copy of the diabetes advice pamphlet I was given in 1972 and it mentions pre-bolusing. Though it doesn’t call it a bolus. Only trouble is if I forget and then its juice or worse in place of the meal.

    02/6/14; 6:53 am
  27. Jennifer #

    I’ve never pre bolused for my DS but after reading this I figured we’d give it a try at breakfast. His numbers were horrible at lunch. We gave it 2 days to make sure the 1st day wasn’t a fluke and his numbers the 2nd day were worse. No more pre bolusing for my sugar baby. I was surprised because it makes sense and I can’t figure out why it was so bad for him 🙁

    02/10/14; 2:39 pm
  28. Jane #

    My doctor suggested using a super bolus (turning off the basal for the hour and adding that amount to the bolus) before breakfast. But I had forgotten bout prebolusing – that might work, if I could plan ahead. Would a prebolus do the same thing? How do you think they compare?

    My A1C was surprising – 8.1 when my average on the monitor was 147. I think it must be because of the highs after meals, when I felt fine, so wasn’t testing. I will try the prebolus with the super bolus, as a back-up plan.

    02/11/14; 11:42 am
  29. I’d pre-bolus a correction at a restaurant but not the actual meal bolus. Too scary!

    On the other hand, I pre-bolus breakfast by 30 minutes or more 99% of the time.

    02/16/14; 1:09 am

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  1. So Maybe Don't ALWAYS Pre-Bolus. - Six Until Me - diabetes blog
  2. Pre-Bolusing for Snacks. - Six Until Me - diabetes blog

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