Do we count fiber carbs when calculating a coverage dose?

Forgive me, I should probably know this, but I only recently started taking humalog with meals - before I was only taking long acting insulin.

Do we count fiber carb grams when calculating a dose?

I ate two slices of double fiber whole wheat bread this morning. My sugar spiked from 150 to 244 2 hours afterwards. So I looked at the grams of carb. The two slices had 46 grams of carbs, but 14 of those are dietary fiber. So do I calculate a cover of 46 or 32?


Did you take insulin to cover 46 or 32? Since you were high, more insulin was needed. Did you eat or drink anything else? If you did, did you cover those carbs with insulin?

It’s frustrating to figure out what’s right for you. You might have to do some experimenting and tracking to figure it out.

Also – some foods can make my BG spike way beyond the number of carbs/fiber. White rice is a prime example. You might have to be on the lookout for foods that do the same to you.

To answer your original question, my diabetes educator taught me to subtract the number of grams of fiber from total carbs when a single serving has more than 5 grams of fiber. If I ate the bread you described, I’d count 32 grams of carbs.

Other people have different opinions. :slight_smile:


Oh I got that it requires experimenting - I saw the formulas that all require you to know that covering ratio, which obviously depends on your insulin resistance. It appears I need 2.1 units per gram of carb, which seems like a lot to me. The starting assumption seems to be 1 unit can cover 5g of carbs.

Oh well - its a learning process. Thanks for the info on fiber carbs

Are you sure that it’s 2.1 units of insulin per carb? Not the other way around?

When you ate those two slices of bread, you injected either 96.6 units of insulin or 67.2 units, depending upon the way you counted the carbs.

For comparison’s sake, I use about 40-45 units of insulin for an entire DAY. (I have Type 1, so I need more insulin than most people with Type 2.)

I’m on an insulin pump and my insulin to carb ratio changes throughout the day from 1 unit per 8 carbs up to 1 unit per 10 carbs.

I’m not an expert but I’ve never heard of anyone using anything close to that much insulin.

It was the other way around. I typed faster than I wrote. I wound up taking 15 units of humalog to get me back down to normal

I would cover for 39, or half of the fiber (if over 5 grams). My CDE said this was something new compared to covering for all of the carbs because some of the fiber does get absorbed, or something like it. I now cover for half, and have had really good luck with it. I used to go hyper a lot more when subtracting all fiber for a bolus.

Mike notes the correct general guideline for subtracting fiber. For a single serving of food with more than 5 grams fiber, subtract HALF the fiber. That’s to account for the soluble vs. insoluble. Some foods, such as cereals, list both soluble and insoluble, but most labels do not give that breakdown.

It’s really only helpful if you eat a food with lots of fiber (like the 15 grams in your bread). Otherwise, you only get to subtract 2 or 3 grams, which doesn’t make a big difference in total units injected, even with a low insulin to carb ratio.

But, eating plenty of fiber is a great thing. It can keep blood sugar from spiking rapidly (it won’t necessarily decrease the peak, but it is likely to give you a smoother increase and decrease over a longer stretch, which allows any insulin your body produces or any that you take to better “match” the blood sugar. It can help you feel more satisfied with your meals.

PS: Forget the rice, Janet. Have you tried barley? High in fiber for a whole grain.

Dear scott.

It shows that even high fiber bread is an unsuitable food for diabetics.

Sadly I don’t have a lot of options. I’ve also got diverticulitis, and the regimen for that is lots of fiber.
I had a fun chat with my doc over that one, since fiber usually brings carbs with it

That much rapid-acting insulin is quite frequently used by type 2s who need meal-time insulin (they battle insulin resistance and diminishing insulin production). Can you imagine the “ouch” of having to push in that much insulin?!

What’s your post-meal goal?

Was the 150 before you ate? If so, you didn’t really spike that high. True, higher than one would desire 2 hours after a meal, but only 94 points up from 150.

If you agree with ADA standards that pre-meal bg should be 70-130 and 2 hours post first bite of meal should be under 180 (Association of Clinical Endos says under 140) and you had dosed for higher carb count (minus only half the fiber grams), you would likely have been very near target if the before-meal number was in range.

But, of course, I do understand how frustrating it is to try to figure out which foods and which doses give us the numbers we want (most of the time).

Do you find that high-fiber grains not made into bread work better for you? Not that they are the same as toast or sandwich bread, but just curious.

In my case I suspect insulin resistance. My weight doesn’t help the situation, of course :slight_smile:

Yes, the 150 was right before I ate. I guess I’m working under an older number, I was trying for under 140 two hours post meal. Thats what I remembered from my first diabetes class back in 1999. I’m starting to think its time to go back to school, so to say.

Oh, I quit eating white rice years ago. I like brown rice a whole lot better anyway and it doesn’t cause the spikes for me. Barley doesn’t either.

Well, not for ALL diabetics. We’re all so different. High-fiber bread is not a problem for me.

I calculate it for the 45 but I am insulin resistant.

The American Association of Clinical Endocrinologists says:
under 110 fasting
under 140 2 hours after start of a meal

American Diabetes Association says:
70-130 fasting and before meals
under 180 1-2 hours after start of a meal