Pre-bolusing: It’s the term that describes taking insulin before eating food. The “before” part in the definition is key, because the amount of time that “before” is can and will vary among people with diabetes. It depends on a few factors, including the amount and type of insulin being used, the amount and type of food to be consumed, current blood sugar levels, and so forth.

It’s one of those things that’s tricky to nail the timing of, but boy, when it works it’s so worth it.

I have two examples to complement that belief, one in which pre-bolusing almost lead to a disastrous outcome and the other in which everything turned out ideally. I’ll start with the more chaotic scenario first.

In this situation, my boyfriend and I spent the night in New Hampshire to attend a friends’ wedding and had a pretty late night, which meant we slept in a little later than we had intended the next day…actually, a lot later. We only had about 20 minutes to race around our room, pack up our belongings, and get ourselves looking presentable before we had to check out of the hotel. Luckily, our scrambling paid off and we made it out in time, but sleeping in cost us the opportunity to enjoy a complimentary hotel breakfast. We decided that it made sense to stop for brunch on our drive back home to Massachusetts, so we Googled a diner that was on our route home and stopped there for a meal.

When we got there, the restaurant was pretty crowded, but we were seated and able to place our brunch orders almost immediately – a good sign. I assumed this meant we wouldn’t have to wait more than 20 minutes or so (that feels like a restaurant standard) for our food to be ready, so I went ahead and pre-bolused my mealtime insulin. After all, I’d ordered a hearty omelet that would come with breakfast potatoes and toast, so I wanted to be proactive about avoiding high blood sugar and get my insulin in system sooner rather than later.

Unfortunately for me, our food ended up coming out later rather than sooner. In fact, we waited nearly 45 minutes for our dishes to finally come out. In that period of waiting, I was getting more and more anxious about my decision to pre-bolus with each minute that passed without food in front of me. By the 30-minute mark, I was close to full-on panic. Even though my Dexcom wasn’t indicating that my blood sugar was low (it held out steady the whole time), I was worried that the system delay in reporting my blood sugars would fail to catch a serious low in a timely manner. I told my boyfriend what was going on, and without hesitating he went to his car to grab some packs of honey that he’d stored in his glove compartment in case of emergency. We talked it over, and decided that it was probably best for me to consume at least one pack of honey because we couldn’t possibly know when our food was going to come out, and at this rate, we wanted to play it safe rather than be sorry. That didn’t exactly lessen the sorrow and stupidity that I felt for taking a pre-bolus (even though I couldn’t have possibly known that our food would be so delayed, I still felt badly about the whole thing), but it was what it was. And ultimately, I felt like I paid the price several hours later, when I was dealing with the very same high blood sugars that I’d hoped my pre-bolus would prevent. So much for making the pre-bolus grade that time…

But that doesn’t mean pre-bolusing always fails! This brings me to my other example. My mom and I had a nice lunch together last week. Before we left to go to the restaurant, I noticed my blood sugar was a little high. I decided to give myself a correction dose, plus one extra unit of insulin, because I knew we’d be eating foods that aren’t typical for me to consume at lunchtime that could result in highs later in the day. So again, I was aiming to be proactive and prevent prolonged high blood sugar.

And this time, the strategy worked great! At the restaurant, I stacked that pre-bolus with my actual meal bolus (not always a recommended tactic, but it was useful here) and rounded out my afternoon with a blood sugar in the 120s – a win in my book. Thanks to my pre-bolus, I didn’t experience any pesky blood sugar spikes and still landed in range, which in turn showcases the power of the pre-bolus perfectly.

So just like anything in life with diabetes, when pre-bolusing works, it’s wonderful…but it definitely requires a little finesse to learn exactly when/how/where to use it.