If you are an insulin-dependent diabetic (like me) and have ever tried dosing your insulin based on the “net carbs” listed on a food label, you have most likely also experienced that you sometimes don’t hit the right dose at all!
I have a lot of diabetes coaching clients who live with insulin-dependent diabetes, and the question of how exactly you calculate the right amount of carbohydrates (carbs) to dose for almost always come up when we discuss meal plans and what to eat around workouts.
In this post, I want to explain the difference between “Net Carbs” and “Total Carbs” and how I calculate the right amount of insulin to take.
What is “Net Carbs”?
The term “net carbs” was coined by the food industry as part of the low-carb marketing craze that started a few years back. It’s not a term that is endorsed by the FDA or the American Diabetes Association, and as an insulin-dependent diabetic, you should be careful about trusting the net carb numbers.
Per the American Diabetes Associations web page: “Companies define “net carbs” as the total grams of carbohydrate minus the grams of sugar alcohols, fiber, and glycerin. But this equation isn’t entirely accurate because some of the sugar alcohols and fiber are absorbed by the body and can affect blood glucose.”
So, if you calculate how much insulin to take based on the declared net carbs, you most likely won’t get enough insulin to cover your carb intake.
How I calculate carbs
I’ve now completely stopped looking at the net carb amount and instead dose for the total carb amount with some small modifications. This works beautifully for me because I (almost) only eat natural foods that I cook myself, and, therefore, don’t get any sugar alcohols.
I do consider the fiber content of my carbs to some degree. If I’m eating a big bowl of salad, I tend to dose for slightly less than the total carb amount, knowing that the dish is relatively high in fibrous carbs. But I don’t look up the exact fiber/sugar content. I think it also depends on how sensitive you are to carbs and how well you know your body.
If you want to be a little more scientific about it (and if packaged food is on the menu), use the ADAs recommendation and count 50% of the sugar alcohols when calculating how much insulin to take.
Learn how you react to different foods
Exactly how much insulin to take really comes down to the specific foods you eat and how you react to them.
When I grab a snack on the go, it’s usually a Quest Protein Bar and with those, I have to bolus for just under half the carb amount. My favorite is Double Chocolate Chunk, which has a total carb amount listed as 25 grams. I usually bolus for 10 grams, which I guess is a combination of the carbs from the sugars, fibers, and sweeteners.
I have tried bolusing for only the “net-carbs” and that was definitely not enough. This doesn’t make it a bad product (I actually endorse having a Quest bar once in a while if it fits your meal plan), but my experience clearly demonstrates how useless the net carb term is for us diabetics.
For me, the conclusion to the total vs. net carbs debate is pretty easy. I don’t think we should care about the net carbs. They don’t indicate the same thing for all manufacturers and they exclude carbs that actually impact our blood sugar.