Pre-Bolus and Post-Bolus - Do others have to use both methods?

For breakfast I normally have to pre-bolus, sometimes as long as 1 hour before I eat. For lunch I can bolus right before I eat without any major spikes. But for dinner I often cannot bolus at that time because my sugar does not seem to rise until I get into bed. If I bolus then I go low and stay low.

I use the Dexcom to see this pattern pretty easily. I know that fats and proteins will slow digestion, but even if I have carbs for dinner my sugars just don’t seem to move at all. And then, as soon as I hit the bed the spike begins.

Now, I am aware of dual wave bolusing, etc, and I often use this feature. But why does this happen almost every night? Does anyone else have this issue? Any suggestions?


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I am new to this b/c i am just starting (with both my pump as well as my cgm) to basal test. i have been on the pump for 14+ years, and have always relied upon my endo to come up with my basal needs. i never learned about them or how to fine tune them, change them, tweak them, etc. but almost every member on this TuD site has at one point or another suggested that i buy and read Pumping Insulin by John Walsh. so my latest journey began. i started to self-educate and be independent from my doctor. it has been a challenging journey to say the least. but my suggestion to you is this: have you tested your basal rates for this time of night? perhaps this is not something that you can correct w/ a dual wave bolus. perhaps it is something else. also, if your basals are correct, can you increase the length of time for the “square” part of your dual bolus? i find that timing can be essential. i have to use the dual wave feature on my pump even for simple carbs like oatmeal. its frustrating, but don’t be afraid to experiment.

best of luck.

I pre-bolus like you for breakfast and wait almost an hour (today even longer was needed). I USED to encounter lows pre-dinner most days, but that was before I was on a pump (and one of the reasons I went on a pump). I have since dramatically lowered my early afternoon basal rates, so that I arrive at dinner near to where I want to start a pre-meal bolus.

The biggest difference I see, though, is that your dinner issue seems to be your sensitivity at that time of day/ What do you do in the hours immediately preceding dinner? Do you work out before your meal? For me, my highest sensitivity to insulin is at lunch time, but I believe most have that at dinner time.

I thought I was the only one! I have to pre-bolus about 15 minutes before I eat, but then anywhere from 2 to 5 hours later I spike and have to correct. It doesn’t matter what I eat, carbs, fat, protein, or any combination, doesn’t matter, I will spike.


What time do you usually eat dinner? What time do you usually go to bed? If your dinner and bedtime are separated by 4 hours or more and your dinner was not unusually high in protein and fat then you may want to look at the basal insulin. Your’e on pump, no?

If dinner was 3 or fewer hours before bedtime then maybe you need to consider an extended bolus as part of your dinner insulin. I use an immediate bolus and an extended bolus for every meal I eat.

I find my insulin needs tend to go down in the late afternoon and around midnight. My basal rates, however, are not a set-it and forget-it thing. They change and I try to roll with them.

I think you can change this pattern with a few trial and error tests.

By the way, I’ve observed in myself what I call the 24-hour metabolic echo. If I were to go low at dinnertime one day, all other things being equal, I will tend to go low again at dinner 24 hours later. This is especially pronounced if I have an extreme low or high. I’m always on the look-out 24 hours later. It’s not usually as extreme as the initial event but it’s there just the same.

It is not unusual to have higher insulin sensitivity in the afternoon/evening compared to the morning. Similarly, the required early morning basal rate is usually higher to mitigate what is commonly referred to as the dawn phenomenon, while the afternoon/evening basal rates are usually lower. What you are describing seems to follow these patterns. However, if your bg does not move after a carb dinner, I would suggest checking your afternoon/evening basal rate - maybe it is too high? In my case, I pre-bolus for all meals, but the wait time is longer for breakfast (can be as long as an hour) than for lunch or dinner (can be as short as 10-15 min). In general, instead of some fixed periods of time, I wait for the bg curve to start bending down.

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Thanks everyone. I am on a pump and the last time I checked my evening basal they did not cause me to go low around dinner time.

I do in fact workout before dinner. I mostly do resistance training (lifting). However, I rarely wear my pump while I workout. And my workouts sometimes last 1.5 - 2 hours by the time I shower and connect back to my pump. After which, I rarely am above 150 after my workout, but if I am above and trending higher I will correct right then.

I also use 2 profiles on my pump. Exercise days and normal days. Its almost always on exercise profile, which is about 25% less basal overall.

Thas, i hear a lot of people at TuD pre-bolus and wait so long before eating their meal. if the insulin starts working after 15 minutes, how do you account for all the time that you are not eating? how high are you before you bolus, and how low do you let yourself go before you eat? i would completely crash if i waited so long to put some food in my mouth. are you micro dosing? are you eating any carbs? how does this work for you??? and, what type of insulin are you on? i am on Novolog.

Daisy Mae

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Lots of questions. Really, everyone has different reactions, absorption rate, etc. What works for me won’t necessarily work for you. For me, I generally don’t see any response from an insulin dose for a long time. The CGM lets me see it, though, so I wait for a response. Once it comes, sure, I have a short window during which I have to eat. My breakfasts are usually 20g carbs or less. At that level, I can wait for “the bend” to eat without a problem. When I’m going to eat a meal with more carbs, (let’s not talk about yesterday! EVER! :wink: ), I have to split it up or I will definitely go too low before the majority of the food hits. I get bad headaches when my BG goes moderately “high” - so I have a strong incentive to try and avoid that happening. To do that, I have to let the insulin start working before I start eating, otherwise, the initial food spike will get me into ‘headache range’ – and even when I get the dosage exactly right, the headache that follows that spike will last a long time.

what on earth do you do at restaurants? are you a pumper? which insulin do you use?

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Restaurants are complicated at best. If I’m going to a restaurant that I know well, I usually decide well in advance of entering what I plan on eating. I make a good guess as to what I’ll need (conservative on the low, side, of course), and take that dose early, then make corrections when I see the food. At unfamiliar restaurants, I wait until I see the menu (and sometimes the food) and hope for the best.
I use Apidra these days, but for me, it starts working around the same time as Novolog did. I like Apidra because it seems to have a shorter tail than Novolog for me.

I always have to post bolus, because I don’t know how much I can eat. It is annoying, but …

Last night I ate my Thanksgiving meal at an Italian restaurant. I had a 4:30 p.m. reservation and arrived a half-hour early. Traffic was lighter than normal. Just before 4:00 p.m. I took an extended bolus of 4.8 units over four hours. I also took half of my expected dinner carb-bolus, hoping we would get seated early.

The early seating didn’t happen but we did get a table at 4:30. My CGM showed my BG skipping along the 70 line so I ate a few Tic-Tac mints while I waited. At that time I thought my aggressive pre-bolusing was going to burn me. To make matters worse, it took about 20 minutes to place our order once we got a table. Fortunately, my BG came up to the low 90’s from the mints I ate in the lobby. I took the second half of the dinner carb-bolus once I placed my order.

Restaurant food and timing can be very complicated. If my BGs turned seriously south after we got a table, I planned on asking the wait staff for a basket of bread, something they can usually accommodate quickly and easily. I had plenty of glucose tabs with me but I’d rather eat real food, even bread. In this situation I have no problem playing the diabetes card!

I didn’t need the emergency bread and we ordered the food along with the drink order to expedite things. My spaghetti and meatballs soon arrived and I had no lows. My post meal BG ranged into the low 150’s and I did take two Afrezza corrections which worked out well.

I’m the same as you, Tamra. I usually begin to spike 2-4 hours later. This is esp so for dinner. I’m vegetarian so I eat very little protein or fat. I’ve tried extended boluses as well as splitting up the bolus manually but just can’t find a solution. The only thing that works is taking another bolus before the spike occurs. I have to be constantly checking my cgm for this to work though!

I’m the same! Every morning I have porridge and have to take insulin 25minutes before. I’m on Novarapid.

It can get so infuriating when your trying to control it and it just won’t!!! I’ve been there over quadrupling my doses and it’s not coming down then eventually it does hours and hours later.

So hard to manage sometimes and makes you think why do you even bother and as when you bother it doesn’t work.

I tend to find sticking to porridge for breakfast and then just soup for my meals stabilise me. But it’s hard to stick to just that.

It can be challenging matching an insulin action profile to a food action profile. Foods act a different speeds from fast to slow. Foods like porridge are relatively fast from my experience. Many of us also are more resistant to insulin in the morning.

Your post-breakfast spikes are probably the result of a relatively fast digesting food out-running your insulin. Have you experimented with other foods like eggs? I’ve found eggs in the morning easier to dose for since they don’t have the quantity of fast acting carbs like porridge does. I ate oatmeal for years and just put up with the post-breakfast highs. I finally concluded that it’s just not worth it.

I understand your frustration but wonder if you’ve tried other breakfast meals.

I am a CGM user and have learned to be dynamic in how I dose for meals. Will try and prebolus for my meals and then wait for the graph to turn down at least by two readings before I begin to eat. Have learned to stage my food order so that the protein and fat are eaten first with the veggie and then the carbs are last. I do follow my CGM numbers and have them on my wrist via a pebble watch so very glanceable. I will add in small bolus additions if I hang too high for too long to help nudge things back down when I know my carb count was a bit off. I will add in corrections as soon as my pump bolus wizard will allow, but I have done extensive I:C, CF, and DIA testing so rarely wind up with stacking issues. And if I have a meal with high protein and fat that gives that prolonged slow trend up will also add in a temp basal increase. That seems to help me more than using a extended bolus.

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Wanted to try this after learning of sugar surfing. Is it possible though with pump and meter no cgm? Thanks

In his Sugar Surfing book, Ponder comments how dynamic bg control can be done without CGM. Here is a quote from one of his Facebook posts: “Sugar Surfing is dynamic diabetes management in the moment. It is also not dependent on what method of BG collection is used. Actually, one of the more successful Sugar Surfers I know practices Sugar Surfing without a CGM. She checks BG levels frequently (15-20 times daily). Obviously, a CGM makes this process based on frequent feedback easier, but a CGM is not absolutely necessary.”

Based on my own experience with dynamic bg control, I do not think I would be able to do as well without CGM. This is not just a matter of convenience. The shape of the bg curve is what is often the most important piece of information needed to make a decision in the moment, and for me this would be difficult to visualize based on even tens of meter readings.


Thanks so probably need to record and interprete lots of data oneself rather than having assistance of cgm.