Carbs and fiber

I’ve had T1D for almost 7 years and was just recently informed that i shouldn’t be counting fiber when i carb count! anyone have any more knowledge of this and any advice? Thanks!

my doc also recently told me I shouldn’t count fiber only when she recently suggested quest bars (they have a ton of fiber and hella low sugar).
Before that and still mostly though I just count carbs as total carbs…that might be a large part of my ups and downs, but I just know that refined carbs (usually less fiber) require more insulin, or like I can/need to bolus plenty of carbs compared to when I have really fibrous foods. For example when I make a salad with sweet potatoes and chickpeas, those are the main carbs in the salad (or like highest) but I still don’t need a lot of insulin because obviously it’s not a lot of carbs, but also cuz the type is different (better)-they’re more fibrous and obviously don’t have sugar, so their carb content has significantly less spike and more lasting power compared to white bread or something…hope this makes sense and helps!!! I mostly think about it in terms of type of food rather than the exact amount of fiber because at this point I kind of know how many carbs things have but I don’t know the exact numbers of fiber content, so I just sort of adjust based on previous experience with that food or food group…

i’m still confused for some reason haha! like for example, net carbs-do i count total carbs or just the net carbs???

My daughter was instructed to count the total carbs using the nutrition label and to ignore the net carb number. She has 40-45 carbs per meal. Total carbs only. :blush:

thank you! im going to my endocrinologist tomorrow morning so i get to talk to her about it aswell

Over the years, there has been a lot of discussion, without any definitive answer about whether carbohydrates in fiber should be counted when calculating a bolus. I began carb counting and MDI in the 1970’s.
Unless I’m eating a type meal that differs strongly from my usual food choices - i.e., either extremely loaded with VERY CRUDE fiber or essentially devoid of all fiber I calculate my bolus based on Total Carbohydrate.
My logic for that is that when determining my Insulin:Carb ratios I used the total carbohydrate count for foods. By being consistent, I’ve had better results - for example, without needing to remember what factors I used when I set the I:C Ratio.
The “net carb” stuff was instigated in “weight loss” concept so that people on those diets could “sneak in” a few more mouthfuls. It wasn’t created to help people with diabetes measure bolus insulin.

My son is 11 yrs old & was just diagnosed in Dec" 17 so we are newly learning but it’s getting easier… Our doctor told us that any food that has 5grams or more fiber to cut the carbs in half. But just that certain food. Make sense??

@sueann and all,

the amount of insulin you need is the amount you need. diabetes is a bit of a science experiment. so if you have a favorite extra fiber-y food, then you go ahead and eat it and you test more. Whatever it is for you, reducing the carbs you bolus for, increase them… whatever the outcome you need to keep your blood sugar in control is what you need.

when in doubt, guess less. then test. as my kid brother the doctor would say “it’s easy to take more medicine”

have a great weekend

I was told by a CDE years ago you count the total cards not any reduced number unless the fiber is over 5 grams per serving then you can subtract the fiber

thanks all! I went to my endocrinologist on friday morning, she is a stony brook (Long Island) doctor (not that it matters that much, just sharing who gave me this information), and she told me to subtract all the fiber! i guess in the end it will just be an issue of trial and error

As a Diabetes Educator, I recommend that you subtract fiber sources as they do not contribute to raising blood glucose. As a matter of fact, fiber can help to stabilize blood sugar, giving you a flatter post-meal result. But obviously, if you have consumed other foods at the same time that are either very high in carb and/or the glycemic index (or glycemic load, if portion is taken into account) is high, that will cancel all the positive effects of fiber in food. Try to include at least one or more fiber sources of food at each meal, if you can.

thank you! that definitely helps a lot!

The issue is not about counting, it’s about not counting. Let’s say that you make a sandwich with each piece of bread having 12 grams of carbs and 2 grams of Dietary Fiber. You delete the fiber carbs from the total carbs, e.g., 12 carbs minus 2 carbs equals 10 + 10 for the second piece of bread, so you should take bolus insulin for 20 grams of carbohydrates. Subtract the fiber from your carbohydrate amount. Here’s what Joslin Clinic says: “Fiber is a type of carbohydrate (just like sugars and starches) but since it is not broken down by the human body, it does not contribute any calories. Yet, on a food label, fiber is listed under total carbohydrate. So this gets kind of confusing for people who have diabetes. Carbohydrate is the one nutrient that has the biggest impact on blood glucose. So, does fiber have any effect on your blood glucose?”

“The answer is that fiber does not raise blood glucose levels. Because it is not broken down by the body, the fiber in an apple or a slice of whole grain bread has no effect on blood glucose levels because it isn’t digested. The grams of fiber can actually be subtracted from the total grams of carb you are eating if you are using carbohydrate counting for meal planning.” Retrieved from Education Programs and Classes | Joslin Diabetes Center. on April 16, 2018.

Fiber is a complex carbohydrate of which some will be digestible and some will not. Thus you may see some increase in blood sugar from fiber but it will take some trial and error on your end to see how fiber affects your child’s blood sugar. For us, we follow the our Endocrinology nutritionist’s advice and subtract HALF the fiber from the total carbs. This seems to work well for us!

Hi Emily,
I’ve been in one of the pioneering research studies since 1988 with one of the top doctors in the nation at the University of Michigan. I was taught to subtract all of the fiber as well, years ago! It can be trial and error as we each have those trigger foods that cause our BS to to skyrocket or to plummet as I’m sure you know! Good luck!

I recently got into a disagreement with a diabetes specialist about this. I’ve always subtracted fiber carbs, because your body does not absorb fiber. It can’t increase your blood glucose if it doesn’t get absorbed, so I don’t count it. You could compensate for including the fiber by fudging your carb ratios, but I think this is a bad idea. Now your carb-ratios will be affected by how much fiber is in your meal. The percentage of fiber-carbs to non-fiber carbs is low, so the error won’t be too big, but this is an easy source of variability to eliminate.

@hardyju, that was probably a good idea. Although when I began carb counting and MDI in the mid / early 1970’s in what was considered “pioneering” I had no idea what effect fiber would have.
Since then, to make things easy, I count all carbs “Total Carb” except in extremely rare meals where fiber content is much different from my usual diet.