Net or total carbs - let's have a heated debate!

(Barbara Greenwood) #1

So, in another keto place especially for people with diabetes, I suggested to a new person with frighteningly high BG’s that avocados were a good thing to eat. An admin said they were too high in carbs for that person - and I belatedly remembered that that place counts total carbs.

Here in the U.K., food labels and nutrition databases automatically subtract fibre. More importantly… fibre is not absorbed, or turned into glucose, and does not raise either BG or insulin. So, I think counting total carbs is… pointless. Especially if it means you can’t eat avocados.

In the other place, I decided not to push it… it’s the kind of place where these are the rules, obey them! So, I’ve brought it over here, where we can have a respectful, science-based discussion.

So, hit me with it. Does fibre raise BG, or cause an insulin response, or inhibit ketosis?


Depends! As with pretty well everything involved in keto, it comes down to n=1. Some people ARE adversely affected by fibre and do need to stick to a total target or drop out of ketosis… Others have a much higher threshold and can go to 30 or more net. It might be that there are certain things that impact and others don’t. So some people will use net with veg but total with nut flours for example.

It is incorrect to say that fibre doesn’t raise BG or insulin because it does for some people. It may not for most but it does for some because they have tested it

The only way to tell what is right for you is to work it out for yourself. Personally, I work on a theoretical total carb count because I don’t track at all. This gives me plenty of leeway so I know that I will be within a net goal.


I agree with @Daisy…test and see what works for you.

I can’t do net carbs. I have to watch total carbs.

Also, there is a difference in digestion whether the food is shredded to bits in a blender, versus eaten as a whole food product. For me, there is a greater release of carbs when the food is pureed, versus eaten as whole food broken down by chewing.

(Todd Allen) #4

As for the diabetic and avocados, they ought to be monitoring their blood glucose and if they are it is not that difficult to experiment and test foods such as avocados and see how they react. As continuous BG monitoring options improve this will become easy, but using a test strip every 30 to 60 minutes is sufficient to get a reasonable picture.

For those who aren’t diabetic monitoring ketones is a good way to see how their body reacts to various foods. I got one of the cheap $3 ebay blood alcohol monitors that fail to discriminate between alcohol and acetone and have found it very useful.

(John) #5

All about how you react, a blanket rule for everyone is kind of dumb IMO. I have a reaction to sweetners that others don’t, I don’t use them but of course don’t care if others do. It’s like the old you can’t eat that cause i’m on a diet.

To me keto is about insulin control, I don’t care what it is made of, if it spikes my insulin I don’t want to eat it. Protein and some things you eat raise it, but nothing to the level a milkshake does.

(Barbara Greenwood) #6

Wow. By what mechanism can fibre raise BG?

Never mind…if it does, it does.

I can eat avocados, no problem. Nom nom nom.


I don’t count fiber in vegetables. Something heavily processed like a Quest bar is a whole other story. I definitely react to those, whereas I feel totally fine after an avocado.


That’s what I was wondering. So do some people actually digest the fiber while others don’t? Is there research on any of this? Since in England labels show carbs minus fiber, I wonder what the government based that on?

So many questions… :wink:

(Jo Lo) #9

I’ve always noticed that Dr. Peter Attia uses total carbs, not net, in all his work.
For example:

Ketones and Carbohydrates: Can they co-exist?

(Camille ) #10

I do the same thing. If it comes in a package, I count total carbs, if it is a whole food, I count net carbs.


Some people can get an insulinogenic response just by taste or texture in the mouth. That’s why some people cannot even eat any type of artificial sweeteners without spiking their insulin.

Fibre is a huge category. It’s like “cars” or “houses”…huge variability. Here’s what I mean:

xanthan gum
resistant starch

These are forms of dietary fibre. All very different, and will affect your body differently.

(Jo Lo) #12

Yes, some may affect it quite a bit, some barely at all.

(Adam L) #13

Makes a lot of sense John but how do you determine if individual foods spike your insulin?

(Adam L) #14

Hi Fiorella, any talk of how a food or even a meal of various foods spikes a person’s insulin interests me greatly, I’d love to get an idea of how foods impact my insulin but I don’t believe it’s possible without multiple lab tests. If that’s right how many people have gone to the trouble & expense of lab testing insulin response to foods? As you & others rightly say we all need to test things for ourselves so if someone really knows their insulin responses to foods that doesn’t really help anyone else !! I’m aware of Richards advice in the faq’s on how we can get an idea of our bodies insulin response to a sweetener;

If I’m understanding correctly the key to this is that the sweetener “doesn’t produce glucose in your blood” so blood glucose going down indicates insulin secretion?

Not sure whether the same method could be applied to an edible substance that’s more complex than a sweetener, such as an avocado? If so that would just confuse me even more as a T2D because I gravitate to foods which see me have a lower blood glucose level after eating which most keto foods do!!

Could people be basing whether they get an insulin response by using this method or is there some other way people are able to say they had an insulin response to x?

Hi Daisy, talking insulin only, how have they tested it? I have a blood glucose monitor so I know all about that, if there is a way to test insulin after eating various foods I would love to do it.


Good point. I believe it is possible but likely not as accurate as testing BG. I have never really investigated it but I believe you see a DROP in BG if you have a marked insulin response. I could be way off here and I should really have only included BG in my initial comment.

@richard knows more about this. And… I have just read the rest of your comment better and see he has already responded. My own logic is telling me the same and that measuring against more complex foods would be impossible. How would you be able to separate out BG and insulin as indicators in a result obtained from eating a food that contains both? I would say then that my initial statement should omit insulin. Apologies.

If you are IR then the chances that it IS impacting your insulin if also impacting BG is a good one though I would have thought. But that is in theory. Can’t prove it!

(Adam L) #16

No dramas - thanks Daisy, it’s a really interesting and complex topic, especially with insulin resistance & T2D added in to the mix. Just trying to work things out & learning how damaging insulin can be so being able to measure it would be amazing. Will just have to ensure its included in my future fasting blood tests & track it that way. Getting back to the topic of this thread I’ve always regarded avocado as “good” - next time I might eat one by itself with a little salt & pepper then test my blood sugar.

(John) #17

Eat em. You don’t have to eat everything, if I try something heavy in maltitol and test my blood sugar to find it is a problem, don’t eat anything with maltitol. Potatoes used to be a favorite, now they do bad things to me the 2-3 times i’ve tested some. No more taters.


Doing testing with a blood glucose meter helps you identify which foods provoke insulinogenic responses.

Another way that requires great skill and patience is learning to listen to your body. When I place sweet flavoured foods in my mouth, I can feel the rush of saliva. Afterwards, I can feel a dip in energy and being slightly cold.