Project Pizza: A Slice of T1D Research with GluAlex


Has there ever been a food more beloved and yet more challenging for people with type 1 diabetes? Something about that high carb/high fat mix makes pizza both incredibly delicious and incredibly difficult to control blood sugar! Here at Glu, GluAlex attempted to find the right pizza bolus. Here’s what he learned:

Project Pizza Night #1:  T1D Exchange Pizza Party

At a recent work event, I decided to dive into Project Pizza by eating one slice of pizza, and bolusing 3.5u with 0.9u extended bolus over 2.5 hours.

Since I only ate one slice, I only kept to a semi-normal insulin intake with just a slight extend. If I were to eat more than one slice, I’d have taken more insulin up front, and extended bolus of 60% taken up front and 40% extended over 3-4 hours.

In this particular instance, I started out at a higher glucose reading than I probably would have liked to at dinner time (170 w/ sideways up arrow).

After eating the pizza, my BG reading climbed up to a steady 180, where it would remain for the evening. When going to bed, I also increased my basal rate by 25% to avoid the high “hangover” the next morning.

Looking back at trial #1 with pizza, I’d probably take a second bolus about two hours after eating at about 20-30% of my initial bolus pre-pizza, which would have been around 1.30u – 1.35u of insulin additionally. I can say in terms of personal management and being on a pump for just around a year, I’ve not experimented enough with “micro bolusing,” but these are the situations where trying can’t hurt! Just keep some juice or something that can bring your glucose up quickly in case you take too much insulin and start to see a rapid drop in BG.

Project Pizza Night #2: A Celtics Game with Friends

With any project like this, you have to have real world experiences involved. This time, I decided to check out a Boston Celtics game with my roommate, and enjoy some Sal’s pizza. Wait until you see this behemoth. One slice again, but was probably the size of 3-4 slices.

The pre-insulin details are quite similar to my first experiment. BG reading on the Dexcom read 184 at 7:55 PM, right after the first quarter of the game (see picture below). I started by taking a 5.10u bolus, with 2.60u of those extended over 2 hours.

What happened afterwards was a bit unexpected. About an hour later after delivering my bolus, my BG dropped at a reasonable and ‘safe’ rate, and at 9:15 PM I found myself rolling at a nice 109 reading on my Dexcom.

Now guessing carb counts isn’t easy, especially with the Sal’s super-long slice I consumed. I will normally guestimate that one ‘normal’ sized slice of pie is around 45g of carbohydrates. In this case, I guessed that this would be around three slices, totaling around 125g of carbohydrates. I felt comfortable at the game at the 109, but knew that rather than rising later on, I was probably going to continue to drop as time passed and the night got later.

By the time I arrived home at around 11 PM, I was already down to 78. Now this isn’t a massive drop over four hours for me personally, but I’m usually wary to sleep at anything under 90. This is where a small nighttime cup of juice comes in!

Lessons Learned

  • Eat more pizza! One slice is NOT a normal meal for me, but more of a light snack leading into a bigger meal. Eat a comfortable portion, don’t be afraid to crank up your insulin dosage for a bit, as you can rest assured when pizza is in the mix, you’re hammering yourself chock full of carbohydrates. In order to fully understand how to dose your insulin with complex meal items like pizza, you have to eat a normal to a large portion. Having one slice is not only just a small amount of food, but it’s not enough food to combat a low, if you do start to have a decrease in BG after taking insulin.
  • I’ve been on Dexcom for maybe six months to date, but I was much more hesitant to try and combat these types of meals while without a CGM. With injections, I found the insulin delivery to be okay, but I had no idea about how to extend on injections before I transitioned onto a pump. The technology available only provides better outcomes in these situations, and seeing the arrow move in real time truly influences my diabetes decision making and makes me feel more confident.
  • Being active in my own life has also been reinforced through my CGM usage. I had challenged myself post diagnosis with half marathons etc., but only went on feeling, rather than seeing what was to come on the screen of my Dexcom. I truly feel that having data before, during, and after exercise has made my workouts more efficient, with less stopping, and I’m able to prepare for certain situations much better knowing where my BG is at before exercising, or eating an entire pizza.

Get a slice of what we learned! Download a pizza pie full of learnings about bolusing for pizza!Pizza Bolus!

 -Alex Rosenblatt/GluAlex


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