Carbs/Brain Function?

[Tatyana]

Im in college and had to take physiological chem last semester....my teacher mentioned that, once the body switches over to using ketones, the body/brain can only run on ketones for a certain amount of time, but i cant remember what he said...it was somewhere between 1-3 months. is there any truth to this?

If you are starving, which a lot of the physiology examples related to, not 'semi-starvation' or a BBing comp diet, then yes, this is probably true.

Death from starvation is typically 1-3 months depending on the amount of fat the person starts with.

This isn't the same as someone on a ketogenic diet, your body can turn the substrates you eat into glucose, and will continue to do so for the brain. You will just have higher levels of ketones in your body as well.

[fits]

Interesting stuff!

Sounds like you have had your head burried in a shit load of books Tat!!!!

whats your diet look like now days?

[Tatyana]

Interesting stuff!

Sounds like you have had your head burried in a shit load of books Tat!!!!

whats your diet look like now days?

I am not comp dieting, so it is quite varied, and I more or less eat clean and eat what I fancy.

Most of my carbs are from veggies, fruits, and beans, but I will still have things like oatcakes, rice cakes, German rye bread.

Protein, I just got off a stint of eating mostly beef for three weeks, I do try and eat a combo of tuna, chicken, turkey, beef, eggs and cottage cheese.

My fats lately are raw nuts, seeds and olive oil.

[capone1153]

Someone posted on another board that you have to have 50g of carbs a day for proper brain function.

there is some truth to this statement.

Under normal circumstances, yes the brain primarily uses glucose as energy. This happens when you eat carbs. IF u go NO carbs then your brain swtiches over to ketones. this is why people who do low carb diets feel tired, they do not have enough to keep them energized but too many to produce ketones so they are forever inlimbo.

[HEFTY-express]

on daves diet i always forget things like dates and where i put stuff
but somehow i feel smarter hahah and dumb for forgetin so much shit

[beezy13]

there is some truth to this statement.

Under normal circumstances, yes the brain primarily uses glucose as energy. This happens when you eat carbs. IF u go NO carbs then your brain swtiches over to ketones. this is why people who do low carb diets feel tired, they do not have enough to keep them energized but too many to produce ketones so they are forever inlimbo.

Thats not what Dave says whenever he's asked about this. Check out his Q&A, hes answers this all the time. He always states you will feel better on his diet, more stable. The only time he talks about the lack of energy is if you try to overtrain on you workout and spend too long in the gym. Also the brain is not using ketones its still using glucose, its just that the glucose it manufactured from a different source since there are no carbs.

[carob999]

It's actually lactate that's the PREFERRED substrate for the brain cells. Astrocytes also shuttle nutrients to neurons.

[RDFinders]

the 50 gram rule came from the ability of ketones to supply energy needs is 30% during the first few days to week towards 70% as ketosis is prolonged. under normal fed conditions the brain is supplied with roughly 120 grams of glucose per day, but can function within a range of 40-120 grams. so acetoacetate provides the bulk of the energy used by the brain b/c fatty acids cannot be used by neural tissue.

on the side note with seemingly people believe that carbs are so unnecessary, the body can adapt to the conditions you put forth, but why try to change how the body is made? with ketosis, there is a major change in blood pH - from 7.4 to 6.8. at that point the body releases electrolytes in order to raise the pH of the blood to prevent denaturing of blood proteins and alter metabolic processes. so is ketosis a fantastic thing and should it be something that is promoted? we don't live in a natural state of ketosis, so i would vote no. carbs are a part of our make up, energy regulation and usage. plus, it stands to reason for some persons following ketotic diets that they appear flat. if the electrolytes are being elminated via the urine to neutralize the blood, they are not residing inside the muscle to help with glycogen storage and make the muscle full. i think suzanne germano is a prime example of why carbs are good during contest prep. she looked healthy and great - which is why she won her class.

[arielkhadr]

That's ridiculous.. I had the best grades in my last quarter (when I was dieting the hardest) this year in school..

[carob999]

The brain can't use ketones per say but it most certainly can use glycerol ( from body fat or dietary fat). The mistake most poeple make is thinking dietary glucose and carbohydrates are the same as BLOOD GLUCOSE , they are not. All potential energy substrates taken in through the diet must enter the Krebs Cycle before the body uses them for energy. Again DIETARY GLUCOSE IS NOT THE SAME THING AS BLOOD GLUCOSE. dietary glucose enters the cycle just as free fatty acids, glycerol, and amino acids. There is no direct route from dietary glucose to blood glucose. I'm not even going to mention the enzymatic system and it's influence on all of this. Also I couldn't write enough about the confusion on ketosis and blood pH .

[th_vai]

That's ridiculous.. I had the best grades in my last quarter (when I was dieting the hardest) this year in school..

You did keto Ariel?

[th_vai]

the 50 gram rule came from the ability of ketones to supply energy needs is 30% during the first few days to week towards 70% as ketosis is prolonged. under normal fed conditions the brain is supplied with roughly 120 grams of glucose per day, but can function within a range of 40-120 grams. so acetoacetate provides the bulk of the energy used by the brain b/c fatty acids cannot be used by neural tissue.

on the side note with seemingly people believe that carbs are so unnecessary, the body can adapt to the conditions you put forth, but why try to change how the body is made? with ketosis, there is a major change in blood pH - from 7.4 to 6.8. at that point the body releases electrolytes in order to raise the pH of the blood to prevent denaturing of blood proteins and alter metabolic processes. so is ketosis a fantastic thing and should it be something that is promoted? we don't live in a natural state of ketosis, so i would vote no. carbs are a part of our make up, energy regulation and usage. plus, it stands to reason for some persons following ketotic diets that they appear flat. if the electrolytes are being elminated via the urine to neutralize the blood, they are not residing inside the muscle to help with glycogen storage and make the muscle full. i think suzanne germano is a prime example of why carbs are good during contest prep. she looked healthy and great - which is why she won her class.

Good to have a good RD onboard, great posts , I tried keto I was doing good, but I just crave carbs so much, im a carb man, I need them to diet for long periods

[RDFinders]

Good to have a good RD onboard, great posts , I tried keto I was doing good, but I just crave carbs so much, im a carb man, I need them to diet for long periods

thanks mex. these late post have had me dig back on my biochem and advance nutrition days. good conversation and learning.

[freak]

thanks mex. these late post have had me dig back on my biochem and advance nutrition days. good conversation and learning.

thats why im on here a lot. episodic events and application are best for retention of concepts, far better then studying for a test then never using the information again.

[carob999]

FROSTY I seem to be mirroring what you are posting. Either nobody cares for the facts or the facts are too complicated to understand.