Diabetes Diary: How Do You Count Your Carbs?

  • 2 Minutes Read

This post describes different carb counting methods and why some methods might be more helpful than others.

Diabetes Diary: How Do You Count Your Carbs?

I hear clients and patients describe all sorts of dietary strategies to control their blood glucose levels. Unfortunately, many people do not understand how to carb count. Not knowing how many carbohydrates are in a meal or snack can impair a person's ability to effectively control their blood glucose. This increases risk for very high blood sugars (> 200 mg/dL) and hypoglycemia (< 70 mg/dL).

Your dietary strategy for effective blood glucose control will depend upon your diabetes diagnosis, type of diabetes medication, and exercise habits. Carb counting is an essential and basic skill that will help control blood glucose since carbohydrate intake has the most direct impact on your blood glucose level.

It's Not Just Sugar

A common mistake that people make is that they just count sugar grams. Whoops! This is an important error since it underestimates the total carbohydrate load of any food that contains starch. Starch breaks down and gets absorbed as sugar into the bloodstream!

Total Carbohydrates

The most common method of carb counting is to count "Total Carbohydrate" grams listed on the Nutrition Facts panel. Total Carbohydrates is the sum of starch (which is not required to be listed), fiber, sugar, and sugar alcohol. This method accounts for the total possible carbohydrate grams that a given food or beverage could provide, regardless of digestibility.

Net Carbohydrates

Another common method of carb counting is "Net Carbs."

Net Carbs = Total Carbohydrate grams - Fiber grams - Sugar grams

This method assumes that there is insignificant breakdown and absorption of fibers and sugar alcohols present in food and therefore, should not be included in carb counts. However, fibers (especially soluble) and sugar alcohols are a mixed bag in terms of breakdown and absorption, and therefore, how much they can affect blood glucose. To account for this problem, the American Diabetes Association created another way to carb count.

If you still use Net Carbs to dose your insulin, then consider talking with your health care provider or diabetes educator about using the American Diabetes Association method. I know that many people like to count Net Carbs since the count is always the lowest, but it can underestimate absorbed carbohydrate grams. That means you might not take enough insulin to cover a meal, resulting in a higher blood glucose reading 1 - 2 hours later.

American Diabetes Association Carb Count

This method of carb counting is considered most accurate for people who take insulin and must be especially accurate with estimated grams of absorbed carbs. This is the method that is most often taught in diabetes self-management training and education classes. However, it is still an estimate. For those of you who use an Insulin-to-Carb ratio to dose rapid-acting insulin at meals (and if you were recently diagnosed and educated), then you are likely using this updated carb count method. Here it is:

Carb Count = Total Carbohydrate grams - 1/2 Fiber grams - 1/2 Sugar Alcohol grams

If fiber or sugar alcohol content is less than 5 grams per serving, then the adjustment will make little difference in the carb count and you can simply choose to use "Total Carbohydrates" instead.

Big Picture

Keeping a detailed log is your key to understanding how different factors affect your blood glucose control. This log should contain date and time for food/drink (with carb count), blood glucose, medication, exercise, sleep, illness, stress, and any other parameters that you think are important. You can track all of those things with MyNetDiary Diabetes Tracker. To learn more about how to use Diabetes Tracker, please read this article.

Note: If you have MyNetDiary Premium, then you have access to all three carb counting methods and can choose which one you prefer to use for tracking.

Happy tracking!

Diabetes->Carbs & Carb Counting Diabetes->Tracking Nutrients->"Carbs: Fiber, Starch, & Sugar"
Feb 4, 2014
Katherine Isacks
Katherine Isacks, MPS, RDN, CDCES - Registered Dietitian and Certified Diabetes Care and Education Specialist (CDCES)

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