Net Carbs

When it comes to insulin administration at meal time, one must take into account their current glucose readings and amount of carbs they consume. There’re currently some debates about how to read food labels when it comes to carbs.

Carbs come in different shapes: simple carbs, complex carbs, fibers and sugar alcohols.

  • Simple and complex carbs are digested and converted into glucose, and must be accounted for. The problem is, food label do not list complex carbs, only simple carbs (“sugars”).
  • Fibers are usually not digested. They provide many benefits, but they ultimately are expelled and not converted to glucose. The problem is, whereas natural fibers are not digested, manufacturers can add extra fibers in one shape or another, which can increase blood glucose. Food labels do not help us with that.
  • Sugar alcohols (e.g.¬†sorbitol, maltitol, etc) are used with “sugar free” food and do contain carbs that are converted into glucose. However, some do not produce glucose. Food labels indicate how much of them are present in total and may even list them specifically, but who can remember which ones matter?

One thing for sure is that when it comes to insulin, it’s a matter of glucose that matters, and that comes from digested carbs. Net carbs refers to the amount of digested carbs that is converted into glucose, and excludes those that are not. Ideally, insulin boluses should be based on this notion of “net carbs”, instead of the total amount of carbs. But that’s easier said that done:

  • Firstly, because the exact nature of fibers in a given food is unknown, it’s not possible just by reading the food label to know whether those fibers will be digested (and turned into glucose) or not. Some say to count them all, some say otherwise.
  • Secondly, a similar confusion exists about sugar alcohols: some say to subtract them all from the total carbs, whereas some say to count them all.
  • Thirdly, some food manufacturers display the net carbs on their products, but the calculation is not regulated and vary from one product to another. Because of this inconsistency, net carbs shown on packages cannot be considered and must be ignored.

So should fibers and sugar alcohols be accounted for, partly accounted for, or not at all?¬†Although there’s no definitive answer, there are a few useful guidelines.

Whole Food

Let’s not forget that this really is a problem with processed food, because it’s unclear what types of carbs are present, and which ones are digested. But this is not a problem when it comes to whole food, because fibers in them are natural and not digested.

A rule of thumb is when it comes to whole, unprocessed food, you can subtract fibers from the total amount of carbs, because those fibers will not be converted into glucose.

And since there’s obviously no “sugar free” additives in whole food, there’s no sugar alcohols either to worry.

Processed Food

Processed food are transformed by a manufacturer and is why carbs counting is confusing. But there’s a popular guideline when it comes to fiber in processed food: add half of them if there are 5 or more grams of them.

For example, if there are 10g of total carbs and 3g of fibers, use 10g because there’s less than 5g of fibers to discount them. But if there are 6g of fibers, subtract half of that (6 / 2 = 3) from the total (10 – 3 = 7), and use 7g.

As for sugar alcohols, many with diabetes avoid “sugar free” food (or consume minimal amounts of them), and thus do not have to worry about calculating them or not.

It’s All About the Diet

When it comes to carbs counting, it’s really the type of diet you choose that matters the most. Here are some useful guidelines:

  • Look for whole food instead of processed food, because you can subtract natural fibers from the total carbs count. Plus whole food provide a wide range of nutrients and complex carbs that are slowly digested.
  • For processed food, if there are 5 or more grams of fibers, subtract half of that amount from the total amount of carbs, as shown above.
  • Avoid “sugar free” and “no sugar added” food because they contain carbs that can turn into glucose, but it difficult, if not impossible, to calculate the exact amount.

A little confused? You’re not the only one. Some stick with total carbs for ease of use. But if you take the time to learn more about the food you eat, you will be able to better adjust your insulin by following those guidelines.



Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>