Counting total carbs or net carbs

I've just been carb counting for a couple weeks now. I am still learning a lot. So far I have not been subtracting grams of fiber from my total carb count-- but I am definitely noticing the trend that my after meal glucose is lower-- sometimes alarmingly low, after I eat higher fiber meals. I'm wondering if subtracting the total grabs fiber from the carb grams might balance out my carb ratio boluses a little bit.

There seems to be a wide range of theories on this topic, what works for you guys?

I am T1 who counts the total carbs (I still use the exchange count method sometimes). This works for me and has for more than 30 years. When I learned to 'measure' my food we did not know about subtracting fiber, or even about counting carbs for that matter. I still follow those same rules.

All you can do is test to find out what works best for you.

I haven't yet learned about the "exchanges" I've ordered several books on these topics though, so hopefully I'll get better at it. I work away from home for weeks at a time-- where the food is served cafeteria or banquet style-- So while I've got a handle on it at home, where everything has a label, counting carbs is going do be much more difficult once I get back to work here. This is just all new to me.

I'd say don't bother w/ exchanges, counting carbs is the way to go. I went "cold turkey" into carb counting when I got a pump in 2008, although I guess it had been common practice for years? One thing that I've found extremely helpful was to get a food scale, I have a digital one that I've had since then. I got it as it had a "label" thing that would give you the nutrition info but, most of the time, I just check the food and measure it. After a while, I have gotten the hang of it pretty decently but, if you can "eyeball" the difference between a 4 oz hamburger and a 6 oz burger and a 20G of carb bun vs. a 40g of carb bun (or, what the hell, a 65G of carb pretzel bun!) it will help you run your BG tighter? If you're on a ship, it might be useful to bring it along to the cafeteria a few times to get a feel for how exactly many G or oz the scallopped potatoes are?

I agree with everything acidrock said. Exchanges is the old school way. Carb counting is much more exact. Fiber is an UNdigestable carb, so that is why its subtracted from the total carb count. If you are not doing that, you will find (as you have) that your numbers will be lower than expected. We also measure and weigh everything. We have found that even when following package servings, its more exact if we follow the weight in serving (ie how many grams of crackers=x carbs as opposed to how many crackers= xcarbs. Also I find it helpful to weigh all fruit. Initally we were told a 'medium' banana was 15CHO but when I weigh out what I thought a medium banana would be and multiplied it by its carb factor, it turned out to be 22CHO. That may not be a big difference in an adult, but in my 35lb daughter is made a big difference. A book that I found helpful all around is "Think Like a Pancreas" by Gary Schrieber. Lots of good info there if you are still learning. You'll catch on, hang in there.

I was taught net carbs which works well for me. I'd second AcidRock's suggestion about using a scale. I weigh almost everything other than green vegetables (which I don't count at all), meat, fish and cheese.

If you do go net carb, your insulin to carb ratio will be higher than if you go total carb. The plate of black beans will require the same amount of insulin no matter how you do the math.


I too weigh everything. I was taught too to subtract fiber, anything above 5 grams and divide by half. I think that is again YMMV (your mileage may vary)...I didn't notice anything different from subtracting fiber from carb I don't anymore. Because you're so new to all this..and doing a great job, I might add, you may just be very sensitive to insulin, etc...

Just count carbs and get a good scale, as Maurie mentioned, Calorie King, good for carb counts too.

Fiber can be misleading. Fiber is defined as indigestible, but it actually isn't. We now know that a fair bit of fiber is actually processed with the help of gut flora and absorbed later in the digestive process.

T2s are often told to subtract the fiber. Also, most of the mainstream low carb diets (like Atkins) suggest subtracting fiber. Fiber does slow down digestion. Subtracting may work for some, but if you are a T1, you may find you need to count total carbs and instead for high fiber meals expect a slower digestion. This is what Bernstein recommends.

I only really consider it on items with very high fiber amounts-- for example, we had some low carb tortilas that were 10g carb each, and 7g fiber. At that ratio, the way they are counted makes a huge difference in the dosing

I do not subtract fiber, my diet only has 90-110g of carbs each day so fiber has little impact and getting the recommended 30+ grams of fiber is imposable without using a supplement of some kind.

You will also find that protein and fat will have a big impact on how your BG responds to carbs and fiber so when you subtract fiber it's hard to tell if subtracting 6g of fiber really has a big impact.

Just eating carbs and fiber will cause a big spike in my BG so I must consider eating a balanced

meal and base my bolus on TAG.