How should bolus insulin be adapted for fiber in food, and for what type of fiber?
Because both soluble and insoluble fiber aren't digested and absorbed in the digestive tract, they doesn't raise blood sugar the way that digestible carbs do. However, some people with type 1 diabetes report that eating large amounts of fiber does seem to affect their blood sugar as a result of intestinal distension. For example, Dr. Richard K. Bernstein, a physician with type 1 diabetes who specializes in diabetes management, has spoken of a patient who experienced a pronounced spike in blood glucose level after eating a large head of lettuce that contained very few digestible carbs.
Generally speaking, though, it is best to deduct all fiber carbs from the total in order to avoid injecting more insulin than needed. Therefore, if you eat a meal containing 25 grams of total carbohydrates, 7 grams of which are fiber, it is safest to bolus for 18 grams of carb. However, if you find that your post-meal blood sugar is consistently too high when you deduct all fiber, you can try bolusing for only half the fiber carbs, which in the above case would be 21 grams of carb.
Answered By dLife Expert: Franziska Spritzler, RD, CDE
Certified diabetes educator and registered dietitian living in Southern California.
The content of this website, such as text, graphics, images, and other material on the site (collectively, “Content”) are for informational purposes only. The Content is not intended to be a substitute for, and dLife does not provide, professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this site. If you think you may have a medical emergency, call your doctor or 911 immediately. dLife does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on this site. Reliance on any information provided by dLife, its employees and other contributors or visitors to this site is done solely at your own risk. Any information you submit to dLife or this site may be published on this site and in other dLife products. dLife retains all rights to all contributions including submitted questions and expert answers.