top of page
  • diabetes_pa

Bolusing for pizza (and other fatty foods)

Today I want to discuss an important and very useful tool in advanced pumping called the “extended bolus” feature (aka dual/square wave on Medtronic). This feature is amazing for high fat foods such as pizza (my diabetes nemesis), hamburgers, Mexican foods, etc. Every PWD knows that these foods are difficult (if not impossible) to manage, but why?

Let me explain through an example...

George loves pizza. Although he doesn’t eat it often (because it isn’t worth the BG roller-coaster that ensues). Today, George had no other choice. He was at a work conference and pizza was his only option. He counted his carbs carefully and gave himself 6 units of insulin though his pump’s bolus calculator. He even bolused 20 minutes early like he was supposed to! Although George hoped that this time his experience with pizza would be different, thirty minutes after he finished eating he began to feel dizzy and shaky. His BG was 55mg/dl. Yikes! He took 3 glucose tabs (12g of carbs) to help normalize his glucose levels. One hour later he tested himself again and got a reading of 300mg/dl! After only 3 glucose tabs? What happened?

Fat delays the absorption of carbohydrates in the small intestine causing delayed digestion. Because of this, George’s insulin kicked in before his carbs did dropping his BG to 55mg/dl. After George corrected with glucose tabs, the carbs from his pizza also kicked in which caused his BG to skyrocket!

How can the extended bolus be helpful in this situation?

The extended bolus allows the user to give a percentage of the bolus now and a percentage of the bolus over time. This is wonderful for high fat meals such as George’s pizza. With this feature, George could have given a small amount of insulin up front, and the rest over time both preventing his low and his high BG ~2hrs post meal.

Unfortunately, there is no specific formula regarding amount of insulin given up front vs. over time. Everyone is different, and different of meals require different formulas. Therefore, a trial and error approach is needed.

 All pumps offer the extended bolus feature. Medtronic separates their extended bolus into two features; dual wave and square wave. The dual wave bolus acts just as the extended bolus previously described. The square wave bolus allows the user to give the entire bolus evenly over an extended period (no bolus up front). The square wave is great to use for “grazing”. I like to use it while I’m eating popcorn at the movies. This way I can bolus for my popcorn and take my time eating it without fear of going low. It is also frequently used in people suffering from diabetic gastroparesis (delayed gastric emptying). A complication of diabetes caused by autonomic neuropathy.

If you are interested in learning more about this, I strongly suggest having a conversation with your clinician or diabetes educator. It’s a great tool and as you all know... with pizza, we need all the help we can get!

136 views0 comments

Recent Posts

See All


bottom of page