Eating with diabetes: Counting ”net” carbs

What are “Net” Carbs? How do they affect blood sugar?
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Since low carbohydrate diets became popular, the phrase “net carbs” has become a fairly regular fixture on the labels of food products. But, if you are not familiar with the term you may be wondering what in the world it means!

There are three types of carbohydrates: starches, sugars and fibre. All three types of carbs are added up and listed as Total Carbohydrates on the Nutrition Facts Label of a food product.

The concept of net carbs is based on the fact that, although it is considered a carbohydrate, dietary fibre is not digested the same way the other two types of carbohydrates (starches and sugars) are. While starches and sugars are broken down into glucose (blood sugar), fibre isn’t treated the same way. The fibre you eat passes through the body undigested and helps add bulk to your stool (among other benefits). The indigestibility of fibre is where the idea of “net carbs” comes in. In fact, sometimes, net carbs are sometimes referred to as “digestible carbs.”

In recent years, food manufacturers have started including net carbs in addition to total carbs when labelling products. Many foods proudly display net carbs on their labels to entice both low-carb diet fans and people with diabetes.

While the concept of net carbs can be utilised in diabetes meal planning, read labels with a discerning eye. At present there are no mandated rules for calculating or labelling net carbs on food packages. Some products calculate net carbs as total carbohydrates minus dietary fibre, other labels reflect net carbs as total carbohydrates minus dietary fibre minus sugar alcohols, and still others calculate net carbs as total carbohydrates, minus dietary fibre minus sugar alcohols minus grams of protein.

Many packaged foods that are marketed as high in fibre low in carbs actually add extra fibre, such as inulin, polydextrose and maltodextrin, to food products to lower the net carb serving. Most nutrition experts agree that these “stealth fibres ” do not have the same health benefits and may not have the same benign affect on blood sugar levels as foods that contain naturally occurring fibre. As you can see, the whole issue of “net carbs” can get tricky very fast. And for people with diabetes, for whom carbohydrate counting and blood glucose control is a serious issue, referring to net carbs on a food label can have serious consequences.

However, counting net carbs can work for people with diabetes who use a meal-planning technique known as carbohydrate counting to help balance their blood sugar levels, when done correctly.

Here’s how a person with diabetes can count net carbs safely and effectively:

  • The food in question must contain at least 5 grams of dietary fibre in the serving size you are planning to eat.
  • Read the Nutrition Facts label or look up the nutrition facts of the food to find both the total carbohydrates and total fibre for the serving size you plan to eat.
  • Subtract HALF the total grams of fibre from the total grams of carbohydrates to calculate the net carbs in your food serving.
  • Always perform this calculation yourself and do not rely on “net carb” totals listed on any food label.

The whole point of counting net carbs versus total carbs is to allow someone to eat more of a carbohydrate-containing food without adversely affecting their blood sugar levels. If you find the issue of net carbs confusing, don’t worry about it. There is no reason to use this technique if counting total carbohydrates works well for you. Both options can work as long as you are doing them correctly and reading “net carb” labels with a discerning eye.

Last modified: December 31, 2020

Written by 12:33 pm Food & Drink