I have heard from so many patients that their blood sugar spikes after eating pizza even if they bolus for the carb. consumed. This seems like a popular myth and I can’t see anything in any studies that supports a particular carb causing spikes. I always figure the person with diabetes is the one in charge and I just tell people to be sure they truely know what the carb content of the slice is and how many slices they eat and if they find they always spike then dose a bit higher in the future. I sure would like to know if any of you very knowledgeable folks have actually tested the pizza theory?
There are dozens of pizza discussions here you can search. Attempting to figure out the infamous pizza bolus is an ongoing enigma:)
Are you a CDE?
Nothing about diabetes is simply doing one thing because there are innumerable factors involved, including most beyond our control. I’m afraid that healthcare professional grossly underestimate the complexity of bolusing. They never explain how protein impacts BG, for example.
This isn’t a myth. It doesn’t have to do with a “particular carb” or higher doses. The high fat content along with carbs is a killer combination with fat greatly slowing down the effect of carbs. So, it’s not just a matter of estimating carbs, which is quite difficult when eating non-chain restaurant pizza & not easy in a chain restaurant either since their carb counts are often inaccurate. What’s diffuclt is not bolusing for the correct amount for carbs, but calculating the timing of when to bolus because of the delayed effect. People on pumps attempt fancy combos of bolusing. Those on MDI take multiple shots to cover one meal–split doses, often an hour or more apart to catch the late spike.
I do ok w/ pizza if I eat frozen, thin crust (which I prefer anyway…crispy! :-)) and weigh it. For a long time I’d run low b/c I wasn’t weighing it and would only eat a couple of pieces but then I read the box more closely and started eating more.
Pizza is difficult. To bolus accurately you must have an accurate carb count, an idea of the amount of protein and fat you will be eating and get lucky with timing. The high fat content of pizza slows down the digestion of carbs. If I were to do a normal bolus for carbs, then I would go low because the insulin peaks before the carbs are digested. Then later when the meal is digested I would go high. I therefore do a dual wave bolus on my pump and usually dose 70% upfront and 30% extended over 1-2 hours (depending on how large the bolus and how much pizza I am eating). This stradegy works well enough for me when I am eating Tombstone and Little Ceasars.
A book called Total Available Glucose "TAG" shows that in laboratory settings the average human can convert 58% of protein and 10-15% fat to glucose that can enter the blood stream. (TAG group) As you can imagine it takes a lot longer for protein and fat to be converted to glucose and can cause a rise in BG much later than one might expect. I think I have read on a forum here that a diabetic with a CGM ate a large steak dinner and nothing else. This meal has minimal carbs, but the steak eater found that his BG climbed from 2-6 hours after the meal. I belive that this is from the protein and fat in the steak being slowly digested into glucose. The digestion of protein and fat into glucose just increases the difficulty of a correct bolus.
The "tricks" I use for pizza are go to a big chain where the nutritional information is available, eat thin or thinner crust and cross your fingers. Besides that repeated trial and error will eventually point you in the right direction.
The “Pizza effect” is not because of the carbs, but because of the high concentration of proteins and fats and how they are converted into glucose later.
This is broadly called “the Pizza effect” and there is a method called “Total Available Glucose” with a corresponding Tudiabetes group discussing it.
If you read the low-carb groups they mostly ignore the delayed bg-raising effects of proteins and fats. In fact a lot of the “measure at one hour or two hour” controversies they address, completely miss the effect. Essentially, carbs can be a red herring for those trying to understand the pizza effect. (Pun intended. I’ve actually had herring pizza.).
What I found was that good old regular insulin was an excellent match to pizza. The new fast-acting analogs are way too fast and result in hypos if I try to bolus with just a single dose - instead I have to spread it out with multiple shots to make it act more like good old regular.
Hi Tim. I’m glad you brought up Regular. When I have pizza while on MDI, I take 1/3 my bolus amount in Apidra, and 2/3 with Regular – and it really works. (I’m on the pump part time, so when eating pizza while pumping, I take multiple shots. For some reason, I never seem to get the extended bolus right.) I’ve also learned to have some salad with the pizza to reduce the total carb intake. Another discussion right now is talking about not feeling well after eating too many carbs even when covered correctly by insulin; I find this to be true for me as well.
The pumps have “square wave” and “dual wave bolus” but neither really mimic the slow onset and long-lasting part of Regular’s activity. I think that’s a shame because Regular is such a good match to many real foods.
When I switched from regular to humalog several years ago, I kept a couple bottles of regular in the fridge but those expired many years ago now. I don’t have pizza all that often today and probably a single bottle of regular would help and could very well last me a year. Back when I was in college (wow, that seems like a long time ago in a galaxy far far away) I lived on pizza (and got very good at dosing for it.)
Insulin is injected in the top layer of the skin. Depending on the type of insulin the speed of absorption is different. Even the skin type, its humidity and the blood circulation come into play.
Carbohydrates are digested and absorbed in the intestine. The speed of absorption is influences by multiple variables and individual factors. One important factor is the content of fat for example because it slows down the digestion of carbohydrates.
To prevent the blood glucose from spiking the insulin action and carbohydrate build up in the blood stream need to be orchestrated in a well balanced manner. The balance is a result of experience that we diabetics will gain over time and the adjustments we will make. Quite obvious every food with a high content of fat is messing up with this fine balance. Most analog insulins are too fast for pizza so you can not inject the full dosage at once. You will have to use dual waves (on the pump) or multiple shots to counteract the carbohydrates that will be continuously absorbed over longer periods of time. In my experience around 30% of the carbs of a pizza will be absorbed much later (around 3 to 4 hours later). Since I am using analog insulins there will be not much active insulin left to counteract these carbs. Thus I will take a second shot at the 3 hour mark and inject around 30% of the dosage initially calculated for the whole pizza. So it takes two shots in a 70/30 distribution.
The bottom line: for an insulin dependend diabetic this is hands on pratical not theoretical. It is no myth at all when you know the mechanics involved. For type 2 diabetics the pizza might actually be more fitting to their impaired capability to produce insulin. Healthy individuals should be able to produce 20 units of insulin per hour at max. For T2 this is often only half the capacity like 10 units per hour. With the slow digestion profile of the pizza this still might fit and the pizza could be digested without spiking. It really depends on the capability for initial insulin response and ongoing production of insulin. If the number of beta cells is reduced to around 30% of the healthy amount (a number often true for many T2 diabetics) then even the pizza will be problematic. So the stage of progression of T2 diabetes is important too.
Don’t know where you read that low carb followers ignore the effect of protein & fat. I’m very aware of what these do & as are other low carbers. Eating very low carb is an education in using protein for energy as about 58% of protein converts to glucose.& understanding its BG effect. Also, since low carb is moderate protein & high fat, the impact of fat is apparent. Not something that most healthcare professionals know. I bolus for protein & so do others.
Even before reading the rest of the posts, I want to put in my 2 cents worth. Dosing for carbs is not an exact science for the faint of heart! You have to realize that there are also fats with that pizza. Fats slow down the absorption of carbs. If you have fast-acting insulin, it stands to reason that the action of the insulin would come sooner than later. If you are a pumper, you may recall that there is a dual-wave bolus and an extended wave (can’t recall the exact term!) to handle if you are grazing over a length of time or if the food you eat gets in your system slower than usual (like fats). This means that, if you are NOT pumping, the timing of the bolus would necessarily peak sooner and also allow for a spike later on in your sugars. Does this make sense to y’all?
I eat frozen pizza, thin crust, cheese only with carb grams listed. Here’s my experience. I eat 27 grams. At 1:4, that’s 7 units Humalog. I start at 100 mg/dL. 2.5 hours later, I’m 264. At that point, since it’s above 200, I have to figure 1 unit will bring me down only 25 mg/dL. I give myself 7 units. Two hours later I’m 150. I give myself 1.5-2 units. Even if I figure 10 grams protein in the piece, at 60% protein going to glucose, that’s only a 1-2 unit deficit, not a 7 unit deficit.
What I’m showing here is that counting the 27 carb grams of pizza wasn’t enough - and furthermore, the cheese/fat was still slowing down the whole process even to 4 hours later. In my body, I know 27 grams should take me up no higher than to 275 mg/dL. But the fat …
It wasn’t the carbs causing a spike. And it wasn’t that I didn’t account for the little protein. It was the fat prolonging digestion, and it was the fat which I couldn’t really figure 10% going into the body as glucose in a pinpointed manner because it’s so slow. If I were on a pump, I’d do a square wave. I’m on MDI, so I hit it as best I can, with a bolus at 2 and 4 hours later. I end up at 100 every time.
The most important thing you can tell your patients is to know their own body. How far does 1 gram carb take them up? How far does 1 unit insulin bring them down. It’s ok to add a unit when above 200.
I do not eat pizza for which I have no gram count. Period. End of story. I like my 5.7 A1c and eating out pizza would destroy it.
So give my story of what to do about pizza. Say "Some people…"
And, what I have done with people, is stand at the frozen food and taken out one after another pizza to show what can be eaten and what will never be “covered” in a day.
