Pizza and Diabetes: How to Eat Pizza Without Sabotaging Your Blood Sugars

A Type 1 writer gives guidelines on how to dose insulin so you can occasionally indulge in high-carb/high-fat foods without making your blood sugars soar.

How to Take Insulin When You Eat PIzzaDiabetes doesn't have to end your love affair with pizza. If you're going to occasionally indulge, do some experimenting and take good notes to figure out the right way to dose your insulin. Photo by Cel Lisboa on Unsplash

Just because you live with type 1 diabetes doesn’t mean you can’t enjoy a few slices of pizza, or lasagna, or Chinese food, or even...a cupcake with buttercream frosting!

(Note: If you’re a hardcore low-carber and you can willfully resist cake and pizza every day of the week, all year long, this article simply isn’t for you!)

Personally, I make sure that most of my diet (80 to 90%) consists of real food, and is generally very low-carb, too. And then that leaves room for the occasional gluten-free carb-loaded dessert (I love baking!) or one of my favorite gluten-free pizzas (white pizza with lots of cheese and red onions...please!).

But managing your blood sugar around those luxury items that are both loaded with carbs and loaded with fat means your usual insulin dosing protocol isn’t going to work. This applies to foods including:

  • Pizza
  • Chinese food
  • Lasagna (most cheese & pasta Italian dishes, actually)
  • Cakes & Cupcakes with buttercream frosting
  • Ben & Jerry’s ice cream

Surprisingly, there are foods that you would think should be on this list that I’ve found simply don’t qualify because they do digest at a more normal rate, like cheesecake! So you really need to take good notes when indulging to figure out what other foods should be on this list for you.

Mostly, I think you’ll find that the 5 listed above are absolutely the biggest troublemakers.

Why You Can’t Take Your Insulin All At Once 

When you eat pizza—or anything else in the list above--you’re not just eating a good serving of fat and a good serving of carbs, you’re eating a lot of fat and a lot of carbs. Even if you’re enjoying only one slice of pizza or one cupcake, taking all of your estimated insulin dose before or even during the meal is going to lead to severely low blood sugars.

(If you currently don’t know how to consistently calculate your “estimated insulin dose” for meals based on your insulin-to-carbohydrate ratio, you need to read Gary Scheiner’s book, Think Like a Pancreas ASAP. This is a critical part of diabetes management with insulin.)


Because all that fat is going to dramatically slow down the digestion process of all those carbs.

Here’s what happens if you take all your fast or rapid-acting insulin at once for these types of foods:

  1. Within 45 minutes to 90 minutes, you will experience a quickly plummeting low blood sugar
  2. Next, you’ll treat that low blood sugar with at least 15 grams of carbs, like you normally would. And you’ll wonder how on earth pizza could be involved in a low blood sugar.
  3. Also, you’ll want to treat it again and again because there is so much “extra” insulin on board from the dose you took for that pizza. While still full of pizza, you’ll feel sickened by the idea of having to eat more but instinctively panicked because your blood sugar is dropping so rapidly.
  4. Then about 3 to 4-hours later, you’ll find that your blood sugar is insanely high, because not only did you eat carbs to treat the low after your meal, the rest of that original meal is finally being digested without any recently-bolused insulin around to help make use of all those carbs. Oy vey!
  5. Then you take a monster-sized correction bolus, and swear to never eat pizza again! You vow to hate diabetes forever because it’s impossible, and it just doesn’t make any sense! You tell yourself you’re a “bad diabetic” for trying to enjoy pizza once every few weeks. Frustration and rage and guilt ensues. And a few weeks later, the cycle repeats itself.

Enjoying Pizza Without Sabotaging Blood Sugars

It’s actually pretty simple, and you can easily determine your own process following the same guidelines if you take good notes next time you have some pizza or a couple of cupcakes!

Example: One entire small gluten-free pizza from Mimmo’s:

  1. I do not pre-bolus. I repeat: I do not pre-bolus any of my insulin. (Pre-bolusing is the act of taking your insulin about 15 minutes prior to eating to ensure that it’s taking action in your blood sugar by the time an ordinary meal starts to digest. But this is no ordinary meal.)
  2. Right as I sit down to eat, I take 4 or 5 units of my rapid-acting insulin. If my pre-meal blood sugar was below 100 mg/dL, I’d probably only take 4 units. If I was starting out with a slightly higher blood sugar, I’d take 5.
  3. Then, I eat my beautiful gluten-free white pizza covered in cheese and red onions, dipping it occasionally in Tiger Sauce!
  4. I make a note of when I finished eating that pizza—assuming that most pizza meals are easily finished within 1 hour. If I really extended my meal over the course of a couple hours, I would pick a time in the middle of that period to note.
  5. About 2 hours from the time I finished eating the pizza—and 3 hours from the time I took my first insulin dose for the team—I will check my blood sugar, and take another 5 units of insulin to cover the rest of the pizza that will start to be digested in the hours to come.
  6. And then, I check my blood sugar again 2 hours after that to see that all is well.

I must add, though, that if I make a homemade gluten-free pizza or I bake one of the frozen, gluten-free pizzas from Costco, I need twice the amount of insulin. Not all pizzas are created equal! And this may be more of an issue with gluten-free pizzas because crust ingredients can vary significantly, but either way: be aware of the differences between your pizzas if you’re applying one pizza’s dosing approach to a pizza from a different place.

The same dosing strategy applies to cake with buttercream frosting (the frosting being the real issue, not the cake), Chinese food, lasagna, and dense ice cream like Ben & Jerry’s.

If you wear a CGM, you can actually see that your blood sugar will remain stable with only half of your meal’s insulin dose, and then, suddenly, around that 2 to 3-hour mark after eating, your blood sugar starts to rapidly rise.

Unless of course, you’ve timed that second dose of insulin to prevent that delayed rapid rise.

What If I Wear an Insulin Pump?

There are a variety of ways you can manage this on an insulin pump.

However,  if you’re watching your CGM, you’ll likely find that you don’t actually need a fancy Dual-Wave bolus. This is a bolus-option on your insulin pump that allows you to program a dose of insulin to be delivered immediately, and then another dose of insulin that is delivered gradually over the course of a set number of hours or minutes.

The reason I think this can cause trouble is that you inevitably still get too much insulin in those first 2 to 3 hours after you started eating when you really need that second dose of insulin to be delivered 3 hours after you started eating. It’s just too much insulin too soon.

How to Apply This to Your Diabetes

Whether you’re experimenting with your blood sugar around a new exercise routine or cake, the idea is to take very good notes on what you ate, when you ate it, how much insulin you took, when you took it, and how your blood sugar reacted...and what you need to do differently to get a different result.

Diabetes isn’t actually random. The problem is that it’s just affected by so many different variables. Many of which we can’t control--but we can predict.

Don’t give in to the “This sucks, I can never get this right,” mentality...and instead, strive to simply better understand what is causing those unwanted and often frustrating fluctuations in your blood sugar.

When it comes to eating, certainly, I’m a big advocate of eating mostly low-carb most of the time, but I really believe in dessert and treats, too. You’ll enjoy those treats far more if you have a better understanding of what your diabetes needs in order to manage your blood sugars around them. Do a little self-studying and enjoy!

Updated on: October 4, 2018
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