Glucose and insulin

The liver stores around 80g of glycogen and the muscles store around 350g (https://www.sciencedirect.com/topic...s-and-molecular-biology/glycogen-muscle-level). Sometimes 100g and 500g are quoted, near enough - for trained individuals the muscle proportion can certainly increase.

Once the muscles have absorbed glucose and stored it, it doesn't come back out into the blood stream.

I'd have to work out the exact conversion, but if we assume equivalence between glycogen and glucose mass, that's ~80g, which isn't going to last all that long, but alongside lipids does mean a person can survive for quite some time without food.

Insulin and glucagon have countereffects in the liver - insulin causes the liver to store glucose (as well as allowing the muscles to use it and fat cells to store it too), glucagon causes the liver to release glucose. There are more hormones involved, but basically if there's a large concentration of insulin the alpha-cells don't produce glucagon, so the liver doesn't release glucose.

You eat, you convert food into glucose, first phase insulin response to convert glucose and insulin lnto energy.
Energy is stored in muscle.
Depending on the individual, and I am one, that can fast for about five days safely without food.
And with my condition, I go low eating carbs.
So I don't.
I use intermittent fasting, and it's very good for me.
You have to find by using testing with a CGM or a glucometer, what is best for you.

Also with my condition and some T2s, we over produce insulin, because of a weak first phase insulin response.
The reaction to this, especially with insulin resistance, is to produce more insulin trying to counteract the high spike of glucose not converted to energy.

Being in keto, the energy is derived differently.

cdpm said:

Yikes!! I need a little more explaining of what you said.
Thanks

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There's not vast amounts of glycogen (which is the stored form of glucose) in the liver, there is much more stored in the muscles, but the stuff stored in the muscles is for their use only, it can't get back into the blood stream to go and fuel e.g. the brain.

The liver and muscles store glucose from your meals when you take insulin; the liver can also release glucose if blood sugar is running low (e.g. you've not eaten)/are being chased by lions (or similar)/have just got out of bed/etc.

In the first instance (blood sugar running low), a hormone called glucagon is released by the pancreas' alpha cells (the beta cells release insulin fwiw) and this hormone tells the liver to release glucose (by breaking down glycogen). However, if there's too much insulin in the blood stream the glucagon isn't produced, so the liver won't release stored glucose.

In the latter cases (lions, getting up - aka Foot on the Floor and its close relative Dawn Effect), it's natural stress hormones which cause the liver to release glucose (to help with fight or flight), from experience even quite large amounts of insulin don't counteract the effects of these hormones.

There's one for the quantity in the first post, the others are actually more complicated than the quick explanation.

I'd have a look at Wikipedia for something that is reasonably digestible with links to more technical papers.

e.g. these would be of interest:


My comment about stress hormones is supposition on my part, I've not looked at whether adrenaline causes glucagon to be released even in the presence of insulin, or whether there's another pathway, though it would appear that there;s something going on as DP/FotF are things that happen even with insulin on board. The full picture (as often the case in the body) appears to be both rather complicated and not necessarily fully understood (or at least not in a joined-up way) which means it's pretty hard to get a useful top level view without reading lots of medical journals. Even then the journal papers tend to be quite specific about some particular part of the chain, or an effect that is being tested, which doesn't help with the big picture view. At least that's my experience - I have always wondered whether there's a suitable degree level text available somewhere which just goes into the detail of the things a T1 diabetic might be interested in. Quite possibly in Bilous & Donnelly's Handbook of Diabetes which I should get around to reading.

P.S. Happy to be corrected!

When I was diagnosed, the best and easiest papers to read, we're mainly from universities in the U.S.
A lot of it was supposition.
A lot was speculation.
And I agree, it is very complicated, and medical journals etc, always use the long words and technical jargon, that you need a medical dictionary or someone like Alan Turing to decypher.
And further to your comments about hormones, with my condition, my first phase insulin response is weak.
However, I was told that my hormonal response with the insulin differed dependent on what I had eaten.
I would add that most metabolic conditions, do have varying imbalances in their hormonal/insulin response, wether first or second phase and if including how the gut interacts with the signalling, to and from the gut, brain axis. It is said that the enteric system has a bearing on which hormones you need through the stomach, intestines etc.
I do believe there is much more to learn from our digestive system that the boffins have no answer for.
The individuality of each of us is imperative in our own diagnosis and treatment.
I had to research and look for other people who had this condition and their outcomes, treatment and anything that could help me.
Then I had to experiment, experience, trial and error, and because of this, I was able to control it.
And thanks to my endocrinologist, who had the knowledge and understanding of that there could be a reason why a non diabetic goes hypoglycaemic after food.
He admitted, he recognised the symptoms that were similar to other metabolic conditions, but found the reasoning to do the tests.
he also told me, that, if I had gone to see his mentor/ professor, he would have said it was impossible to have such a condition. My first endocrinologist five years before, thought it was a fatty liver, nothing else and told me to knock off the drink, when I told him I had been teetotal for the last five years, he didn't believe me.
then of course there are opinions in the medical hierarchy and closed minds.
The more they discover and find, the likelihood that they discover how food impacts our metabolism.
And the numbers of the population affected by intolerance and allergies.
The epidemic of T2, should have those in the medical hierarchy, making sense of how our staple foods can be so unhealthy for a large proportion of the population.

cdpm said:

We apparently have 1 or 2 days of glucose stored before we run out? So why would insulin use cause low blood sugars if too much was used without new glucose intake?

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Glucose is fuel for the brain and the glucose gets to the brain via your blood. Hence you need a certain amount of glucose in your blood otherwise your brain will quickly shutdown, i.e you go into a coma.

When you eat, carbs gets converted to glucose and absorbed into your blood stream.

But too much glucose in your blood is also bad and insulin is used to move glucose out of the blood and into storage (e.g. the liver)

Non-diabetics will stop producing insulin when their levels are low enough and may instead produce glycogen which releases glucose back into the blood stream.



Diabetics will also produce glycogen which will try to release glucose back from the storage. But we can't get rid of the insulin that we have already injected which means it may be removing glucose from the blood stream faster that the glycogen releases it.


Edited by mods to remove forum rule breach

sgm14 said:

Glucose is fuel for the brain and the glucose gets to the brain via your blood. Hence you need a certain amount of glucose in your blood otherwise your brain will quickly shutdown, i.e you go into a coma.

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sgm14 said:

But too much glucose in your blood is also bad and insulin is used to move glucose out of the blood and into storage (e.g. the liver)

Non-diabetics will stop producing insulin when their levels are low enough and may instead produce glycogen which releases glucose back into the blood

Diabetics will also produce glycogen which will try to release glucose back from the storage. But we can't get rid of the insulin that we have already injected which means it may be removing glucose from the blood stream faster that the glycogen releases it.

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Hi, I was regularly informed about this hypothesis that constant carbs are a necessity for brain function from the majority of my doctors and my endocrinologist.
So when I did a 72(80 really) hours fasting test in hospital. I felt really good for the first in a long time. My endocrinologist was surprised by this, and I have done many multi day fasts and been zero carb for many of the twelve years since diagnosis.
After much consideration my endocrinologist came to the conclusion that carbs were not needed for brain function, as the body will adapt.
Yes you do need blood, but how much is debatable. Because it is what percentage of hormones, white and red cells etc is in the blood. The breakdown of differing levels of hormones etc, has a direct impact and effect of symptoms on you. It also has an impact on how your brain reacts to sensing the imbalance. And how much hormonal response is needed.
I would add that if you are getting your energy from carbs, to stop or go cold turkey is not recommended.

Too much insulin is worse than too much glucose and depending on your imbalance of Insulin production, either will be an issue, as will any hormonal imbalance.

My condition does not do this, my overshoot of Insulin to the glucose derived from carbs, will always put me into hypoglycaemia. Having spikes and hypos, does make you really ill. And I'm not diabetic.

Metabolic conditions are so individual, it is not as straightforward as in the medical profession tell you.

Best wishes.

cdpm said:

So does fasting use up some extra not needed stored glucose? Sorry if this was explained already.

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The body naturally adapts to fasting.
But some T2s are unable to fast.

Lamont D said:

After much consideration my endocrinologist came to the conclusion that carbs were not needed for brain function, as the body will adapt.

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I didn't mean to say (or imply) that carbs were needed. Indeed I was under the impression that this was generally accepted - based on the observation that before insulin was discovered, most type 1 diabetics still died even if they avoided all carbs.

Apparently my message was edited to remove the 'patronising' bit where I said it was overly simplistic (it was supposed to be an ELI5) . So whilst I did said that 'carbs gets converted to glucose and absorbed into your blood stream' this is indeed overly simplistic as it is not the only way that we can get glucose - it just happens to be the most common.

So I would agree that carbs are not needed for brain function, but I still think glucose is needed or do you (or your endo) disagree?

Energy is needed for brain function. Lots of it, and the general assumption is that this means glucose, but the brain will happily work with ketones and some other less well known fuel types.

The big issue with the brain is that fats cannot be used as fuel - the brain uses fats as construction and needs smaller molecules for fuel.
The second big issue is that for many people on a carb-heavy diet, there simply are not enough ketones being produced, and like most tissues, it's either or.
The third big issue is that with insulin resistance, (as most Type 2 will understand) - the brain needs more and more glucose to function properly.

You are 100% correct @cdpm - I had that same argument with a very strong-willed consultant, but yes, your liver is pretty amazing and will convert excess protein into glucose.

sgm14 said:

I didn't mean to say (or imply) that carbs were needed. Indeed I was under the impression that this was generally accepted - based on the observation that before insulin was discovered, most type 1 diabetics still died even if they avoided all carbs.

Apparently my message was edited to remove the 'patronising' bit where I said it was overly simplistic (it was supposed to be an ELI5) . So whilst I did said that 'carbs gets converted to glucose and absorbed into your blood stream' this is indeed overly simplistic as it is not the only way that we can get glucose - it just happens to be the most common.

So I would agree that carbs are not needed for brain function, but I still think glucose is needed or do you (or your endo) disagree?

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No, I don't disagree at all, in that the body adapts.
And I appreciate your thoughts on it all.