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My brain might be hungry

HSSS

Expert
Messages
7,675
Location
South of England
Type of diabetes
Type 2
Treatment type
Diet only
No I’m not a zombie hungry for brains. Just feeling like a zombie without a brain today

But if our brains require approximately 150g of glucose a day to function, doesn’t that mean we (T2 with our own insulin) should all be able to eat that many carbs at least, knowing our brain will burn it regardless of whatever our other cells fail to do because of insulin resistance? Or are our brains insulin resistant too? and only snacking on the glucose feast 150g of carbs a day would represent to those of us on keto rather than eating it all?

Just how much gluconeogenisis is required when keto to provide the brain with the smorgasbord of glucose it seems to want in oreder to allow it to pick and choose nibbles whilst ignoring the bulk of it? It appears it might ultimately use 150 a day but it can’t use everything that’s offered so needs more offering, based on the first question I asked above, leaving the unused leftovers to sit in the blood and end up as fat cells.

Now I’ve typed this I‘m thinking if other cells can be IR why not the brain and it seems a silly question but I’ll ask it anyway.
 
Not sure about where our brains get their energy from in the absence of carbs, think I've read some where that we can manufacture enough for our needs.
I do know that on the few extended fasts I've done my brain has been as sharp as a pin, so it must have been getting fed from somewhere. And yet when I've been seduced by the dark side and had more carbs than I should, it's guaranteed to make me sleepy
Talking of the dark side, I'm struggling to forget the image of you as a brain eating zombie
 
Our brains can run on Ketones, but do need some Glucose as well. Our livers can provide the necessary Glucose, hence there is NO requirement to consume carbohydrates.
I think but don't know for sure, that higher Glucose levels do affect the working of the brain. Like a car engine running rich (too much fuel).
with lowered Glucose levels it seems a lot more efficient.
 
Oh I know we can run on ketones and gluconeogenisis in the absence of carbs.

I’m wondering why the brain isn’t using the first 150g of carbs/glucose we eat a day though

Put another way why can’t we eat that amount at least before it gets stuck in the blood.
 
Might it be because we are in caveperson mode? Which drives us to catch some food or run like **** rather than use much of our thought processes at the start of the day? Of course, we still need to think even then, but brain/body interface probably prefers us to be more physical.
 
I guess if it uses around 150g per day, it doesn't need that 150g all at once, it probably can't even use it all at once. What's not needed right then causes all the normal problems we know.
 
Lobsang Tsultim said:
I guess if it uses around 150g per day, it doesn't need that 150g all at once, it probably can't even use it all at once. What's not needed right then causes all the normal problems we know.
Click to expand...
Which suggests we’d need to drip feed 150g over the entire 24hr. Mmm
 
Antje77 said:
Maybe it does, but then the glucose your liver produces get stuck in the bloodstream I guess.
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which suggests for those eating much lower than 150 that the liver is producing quite a lot to make up the difference and make enough to get stuck. Anyone know how much livers kick out?
 
HSSS said:
which suggests for those eating much lower than 150 that the liver is producing quite a lot to make up the difference and make enough to get stuck. Anyone know how much livers kick out?
Click to expand...
People on keto seem to do well, so the liver must kick out enough for the brain to run on.

As a T1, I need a more or less fixed dose of basal or background insulin, regardless of what I eat.
It works to keep me steady when not eating, so apparently the liver trickles the glucose in a steady amount all day, regardless of current BG or food and my basal deals with that.
And occasionally the liver gives an extra glucose boost, when suddenly stressed, or when waking up, or when having a hypo.
 
Dawn phenomenon rather proves the liver can and does kick out a lot more glucose than most of us types 2s can cope with.
 
If the brain uses 150g glucose a day, that's only 6 or so grams an hour, which presumably it takes from the blood to replenish it's own stored amount as and when needed. Presumably when our blood levels are high, the hyperinsuliemia forces too much glucose into the brain cells causing the fog.
 
Well despite some indications to the contrary my brain is still functioning so it’s obviously sourcing the glucose somewhere. I’m not concerned about it failing to. Ketones can supply additional needs but don’t totally replace the glucose the brain needs. I was just curious where it’s getting it from. It’s obviously partly to do with the liver adding to the overall glucose available as your T1 situation proves. If a person is eating less than the required 150g glucose the difference must be coming from the liver as there’s no other options really. Therefore if eating just 50 the liver must be producing a minimum of 100 a day, quite possibly more. (Hence why Metformin helps as it reduces that production). As I mull this over during the day I guess I’m wonder how much extra the liver is adding.

I’m also wondering if insulin resistance means that In order to take up that 150g over the day significantly more needs to be available because IR means I’m useless at the uptake (Bit like filling a bath with a leaky bucket needs more water supply)

this is just one of the random thoughts that gets stuck in my head some days Lol
 
I think rather than more glucose it's a case of more insulin. unless there is some sort of signal from the brain to say pull your finger out i'm still running low on gas here!
 
While carb counting to determine your insulin dose isn't as exact as some people like to think, it does work more or less for many people.

So if a T1 knows their insulin to carbs ratio you should be able to calculate the other way and determine how many carbs were produced!
Mind, I'm not at all believing this will lead to a correct answer, but there might be something to it.

Let's take a pretty average T1 with a 1:10 IC ratio on 20 units of basal (I think that's pretty average, didn't look it up though).
On a 1:10 ratio, 20 units spread over the day should cover for 200 gr of carbs, eerily close to those 150 grams you mentioned. (how did they even work out how much glucose the brain needs?)

Let's now take a not so average T1 (myself) with a I:C ratio fluctuating between something like 1:1 to 1:3 on +/- 110 units of basal.
Averaging the ratio to 1:2, my 110 units of basal should cover for 220 grams of carbs. Amazingly close to that average T1 and those 150 grams you mentioned.
I'm completely surprised by the outcome of my own calculations, I was just giving it a try!
HSSS said:
this is just one of the random thoughts that gets stuck in my head some days Lol
Click to expand...
Same, and not a bad way to spend some time!
 
ajbod said:
I think rather than more glucose it's a case of more insulin. unless there is some sort of signal from the brain to say pull your finger out i'm still running low on gas here!
Click to expand...
You think we need more insulin? Most of us t2 have more than enough though!
 
I’m so glad you did the maths there. I was thinking to myself as I started your post how on earth would I work that out. It does make sense though. When you consider that we actually need to ingest zero carbs it stands to reason that’s because the liver makes enough to feed the brain plus a little extra.

So the brain is the cannibal zombie eating the liver (‘s glucose) and anything else we stuff in our mouths needs the insulin (bolus or endogenous) to cover the intake, accounting for any IR we have. Pretty much the way I‘ve always thought of it but from a very different angle Lol. Good to test my understanding i guess. Apologies @catinahat for bringing the horror movie characters back into the discussion.
 
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