Fiber and insulin

(mole person) #1

I know that we deduct out net carbs because there is no calorie or glucose impact of dietary fiber. However a lot of ketogenic diet experts recommend total carbs and I’ve heard some suggest that there is still a metabolic impact that affects fat loss. I’ve also read that proccessed fiber is more insulinogenic than unprocessed suggesting an insulinogenic impact of the fiber itself.

If fiber is insulinogenic then it’s something that requires some consideration in its own right.

I’m interested in studies that show whether fiber, both soluble and insoluble, is or is not insulinogenic.

Any help would be greatly appreciated!

(Bob M) #2

I did some searching for this, and it’s tricky. Most of the results are epi garbage. I was under the impression, though, that fiber might get fermented to short chained fatty acids. See this, for instance:

https://chriskresser.com/myths-and-truths-about-fiber/

Virta also had an article on this:

https://blog.virtahealth.com/fiber-colon-health-ketogenic-diet/

Neither of these mention insulin, though. They mention the epi garbage studies where people who eat fiber have less insulin.

(mole person) #3

Thanks @ctviggen. I’ve really tried to find some evidence that it’s not insulinogenic but instead all I found was something that suggested the exact opposite.
https://www.google.com/amp/s/medicalxpress.com/news/2018-03-fiber-supplement-insulin-secretion-diabetic.amp

Levels of blood sugar, insulin and proteins involved in inflammation were measured in the patients after they consumed a high-fat, high-carbohydrate meal. The same patients consumed the same meal a week later, but this time they also consumed Fiber One (a commercially available supplement) before and after the meal.

“After eating the meal, diabetics’ insulin secretion increased significantly after the fiber.”

(Full Metal KETO AF) #4

@Ilana_Rose if you’re eating carnivore almost everyday with only occasional vegetables why are you concerned with the insulinogenic reaction to fiber? Normal insulin response is the goal, you can’t live without insulin. Your body needs it for using proteins and lots of other functions besides dealing with glucose. If someone is really concerned about this Total Carb tracking makes sense to me, but Carnivore and occasional vegetables shouldn’t require carb tracking at all, or wondering if the amount of fiber you eat increases insulin which would seem insignificant with that dietary scheme. :cowboy_hat_face:

(mole person) #5

Because I have interests in nutrition that go beyond the items on my plate. Understanding what makes the ketogenic diet effective has been a huge interest of mine for two years now.

Whether to count net or total carbohydrates happens to be a specific area where the expert opinions seem to differ and so teasing out the reasons for this and understanding the evidence supporting those reasons is necessary to come to my own conclusions.

Finally, the idea that fibre is metabolically neutral and specifically that it has zero effect on insulin is bandied about on these forums. Don’t you agree that it would be better not to believe things that aren’t true?

Regulating insulin response is what the ketogenic diet is all about. It’s why we limit carbs. If fibre has a similar insulin profile than the only point of it is the same as there would be on the SAD. That it fills your tummy and has no calories.

Literally everything we eat results in an insulin response and low insulin is simply not a problem except in people in a disease state. We have loads of people here with hyperinsulinemia. Some of them struggle to lose any weight at all without extended fasting because their insulin response to food is simply too high. So identifying foods that have an impact on raising insulin without any concomitant benefit is the entire point of this way of eating.

(Full Metal KETO AF) #6

I have been eating a ketogenic diet for 11 months. When I started my fasting BG was about 203 after 12 hours. My HbA1c was 6.7, I was just tested again last week and fasting BG was 112 and HbA1c was 5.4. I have never tested with a BG lower than that. I was pre diabetic but I am told not now. But I still have the higher fasting BG levels. I am on prednisone so that probably is the cause for the elevated glucose readings. I still don’t have a clear picture of what my insulin response is like. I have read many times that if your BG is too high there’s too much insulin and you won’t be in ketosis, but I have lost 50 lbs. anyway eating this way. So the whole subject isn’t straight forward for me. I keep reading about full blown T2 people going from a BG of 400 to less than 100 in a month and getting off insulin but I am not even a diabetic and still after almost a year I have never gotten that low. It’s frustrating if I let myself think about it, like my efforts aren’t being successful but I seem to be loosing weight and doing well in other respects and my doctors are happy.

(mole person) #7

I think that you are doing fantastically, honestly. You have had many serious health issues that most of us don’t face and have had dramatic results in spite of them. Your progress should be an inspiration to anyone thinking about trying a ketogenic diet.

(Failed) #8

I’m one of those, although I was not taking any meds for it. What I found is that protein raises my BG nearly as much as carbs, so I’m going as low protein as I can.

I haven’t been keto for very long, so that may change.

(Bacon is a many-splendoured thing) #9

I’m not sure what you mean by “processed” fiber. If you mean the sort of processing that turns a fruit into juice, it pretty much destroys the fiber. That is why apple juice has such a more powerful effect than eating the equivalent number of apples, for example.

Dr. Lustig, on the one hand, believes that fiber is benign, even beneficial, for a number of reasons. His take is that intact natural fiber is nutrionally null. Dr. Westman, on the other hand, requires his patients to count fiber as part of their carb intake, and I have recently heard that he is now saying that even fiber has an effect on insulin.

This may be an area where the science is evolving, so I would suggest care in eating close to one’s limit. We might start urging newbies to count total carbs, instead of giving permission to count net.

A complicating factor, of course, is that everyone’s carb tolerance is different; lower, if you are highly insulin-resistant, higher, if you have a normal insulin response.

#10

As far as I know, fiber doesn’t do anything beyond limiting how other carbs are absorbed when the foods containing them are in their natural state. Removing the fiber then adding it back in doesn’t restore the original digestion profile, which is why some people use net carbs for whole foods but total carbs for processed ones. It’s a shortcut to preserve sanity. Otherwise you’d have to look at the glycemic and insulin response for every ingredient in its processed state, if that data even exists.

That and the ability to produce SCFA in the colon through fermentation with gut biota.

(mole person) #11

Juicing is generally fiber removal. Processing refers to things like grinding. Flour is a proccessed wheat. The insulinogenic properties of whole wheat flours are not the same as say, eating the whole wheat berries. I’ve heard keto doctors many times now implying that the same is true of grinding almonds for almond flour, for example. Again though, I’ve not, as of yet, seen the evidence that suggests this conclusion.

(mole person) #12

Is there a study that shows this? We often get newbies who think that their proccessed bars are good to go because the net carbs are low. It’d be great to give them something other than opinion based on what I’ve gathered from podcasts etc.

Also, do you know anything about this question of grinding affecting the insulinogenic properties of a food? It sounds plausible, but I’m never confident about the quality of information gleaned even from expert opinion without seeing some sort of evidence.

#13

There’s links to studies about different processing and absorption of starches at Break Nutrition podcast - some of early episodes. I don’t have a link handy on phone. Basically, where they are absorbed in the digestive tract determines incretin response which alters insulin.
The further they go before digestion and absorption, the less response. It takes longer to break apart intact foods than pulverized ones just because of surface area exposed to digestion with powders etc. Think of grinding as being fast-acting vs slow-acting.

(mole person) #14

Thank you, @carolT. You are the best. That explains it perfectly. I’ll look for those podcast links.

#15

It was episodes 7 and 8 that I think are the most relevant.

https://www.breaknutrition.com/episode-7-processed-starches-affect-metabolic-responses/
https://www.breaknutrition.com/episode-8-starch-digestibility-limitations-glycemic-response/

(mole person) #16

Thank you, @carolT. This is today’s listening now.

(Bacon is a many-splendoured thing) #17

A lot of people I know take the whole fruit and pulp it, which they consider good, because fiber. What they seem to overlook is that macerating the fiber destroys it and means that it becomes digestible carbohydrate instead.