LCHF or Ketogenic Diet

[Mrs. B]

This is patently wrong. The brain cannot burn fat; it can only burn carbs. That's Biochem 101.

No, that is not really true. You need to get back to us on that.

Substrates of Cerebral Metabolism - Basic Neurochemistry - NCBI Bookshelf


Uses in the heart, brain and muscle (but not the liver)
Ketone bodies can be used as fuels, yielding 2 GTP and 22 ATP molecules per acetoacetate molecule when oxidized in the mitochondria. Ketone bodies are transported from the liver to other tissues, where acetoacetate and beta-hydroxybutyrate can be reconverted to acetyl-CoA to produce reducing equivalents (NADH and FADH2), via the citric acid cycle. Ketone bodies cannot be used as fuel by the liver, because the liver lacks the enzyme β-ketoacyl-CoA transferase, also called thiophorase. Acetone in low concentrations is taken up by the liver and undergoes detoxification through the methylglyoxal pathway which ends with lactate. Acetone in high concentrations due to prolonged fasting or a ketogenic diet is absorbed by cells other than those in the liver and enters a different pathway via 1,2-propanediol. Though the pathway follows a different series of steps requiring ATP, 1,2-propanediol can be turned into pyruvate.[8]

The heart preferentially utilizes fatty acids as fuel under normal physiologic conditions. However, under ketotic conditions, the heart can effectively utilize ketone bodies for this purpose.[9]

The brain gets a portion of its fuel requirements from ketone bodies when glucose is less available than normal (e.g., during fasting, strenuous exercise, low carbohydrate, ketogenic diet and in neonates). In the event of a low glucose concentration in the blood, most other tissues have alternative fuel sources besides ketone bodies and glucose (such as fatty acids), but the brain has an obligatory requirement for some glucose.[10] After the diet has been changed to lower blood glucose utilization for 3 days, the brain gets 25% of its energy from ketone bodies.[11] After about 4 days, this goes up to 70%[12] (during the initial stages the brain does not burn ketones, since they are an important substrate for lipid synthesis in the brain). Furthermore, ketones produced from omega-3 fatty acids may reduce cognitive deterioration in old age.[13]

 

[Storker]

there is NOTHING you can do workout wise to offset the cookies, donuts at the office and ding dongs you intake. Nothing…

Bovine manure. Weight gain = calories in - calories burned. It ain't rocket science, it's simple arithmetics. Eat 200 kcal, burn 200 kcal and you're back to square 1. Eat a donut, run xxx km, and you're fine.

Problem is, you have to run a heck of a lot of kms to offset a box of donuts or an economy-sized bag of crisps.

 

[RyanT]

As to your hard exercise comment – there is NOTHING you can do workout wise to offset the cookies, donuts at the office and ding dongs you intake. Nothing… Even 8 hours of working out per day won’t do it.

If this were true, the vast majority of us would tip the scales at around 800 lbs.

 

[stuartv]

This is patently wrong. The brain cannot burn fat; it can only burn carbs. That's Biochem 101.

Uhhh, maybe you should at least try to move into the Iron Age?

"The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as β-hydroxybutyrate (βHB) "

KETONES SUPPRESS BRAIN GLUCOSE CONSUMPTION

 

[Storker]

that is not really true

It's true. You said so yourself:

the brain has an obligatory requirement for some glucose.[10]

IOW, the brain needs carbs. Can't do without. That's what "obligatory" means.

 

[Storker]

The brain is dependent on glucose as a primary energy substrate

Quoted for truth. Emphasis added by me.

 

[stuartv]

So, my diet started out as a KD, but I stopped testing to see if I was in ketosis. What I found is that at the beginning, yes I was in ketosis… As I got further into it, I was dropping weight quickly, but the level of ketosis was significantly down. It got to where I was at a “trace” or .none…”

I saw a video a while back that said your body could burn the ketones faster than it can produce them, and you’re still in ketosis but not evident in a pee strip test.

Do you agree with that?

I just see much difference between a KD and Adkins.

Your body uses ketones for fuel. If you have excess ketones, you excrete them in your urine. That is what the test strips show. If you don't have any excess ketones, the test trips will show nothing. But, just because you don't have any excess ketones to piss away does not mean that your body is not breaking down fat and using the ketones for fuel.

I started mine with a 2 day keto fast – 2days of green drink and avacados. That jump starts you into ketosis. As to your hard exercise comment – there is NOTHING you can do workout wise to offset the cookies, donuts at the office and ding dongs you intake. Nothing… Even 8 hours of working out per day won’t do it.

Edit: BTW - switching between the 2 is not easy. I made a decision to stay on KD/Adkins and not go back to carbs

I don't think that is really correct, but I also think you didn't make a clear statement. If you eat 1000 calories of donuts, and that is all you eat, and you do a hard workout, you are going to burn more than 1000 calories that day. In that case, I believe you WILL lose weight.

But, when you say "nothing you can to to offset the donuts", perhaps the better way to say that is "there is nothing a workout can do to offset the damage done to your body, even if you burn the actual calories off and don't gain any weight." Because you will still have the blood sugar spikes (and crashes), the insulin spikes, and the gradual beatdown of your body's insulin sensitivity.

 

[stuartv]

Earlier, I said:

your body will feed your brain using fat for fuel.

And you said that is patently wrong.

This is patently wrong. The brain cannot burn fat; it can only burn carbs. That's Biochem 101.

Noting that I did not say the brain burns fat, I said the body uses fat to feed the brain (ketones). I have cited a source for that information.

Quoted for truth. Emphasis added by me.

So, as far as I can tell, you are either wrong, or making a largely irrelevant, tangential statement that advances the conversation by zero.

I assume you do not dive Nitrox, either, as that is voodoo gas? And you believe that cigarettes are good for your health?

 

[stuartv]

The "Bronze Age" brought us all kinds of medical and nutritional wisdom.

 

[stuartv]

The main way it benefits you (as a diver) is that you do not have the "crashes" when you need to eat.

I'm not sure how that really has a tangible benefit to my diving. I have never had any kind of issue when diving that I think could have any relationship to a blood sugar crash.

On the other hand, if a KD really does provide significant reduction in the risk of OxTox, then that seems to me to be a very tangible benefit. Especially for myself, as a technical diver, where I might do a dive where I spend 30 minutes (or more) at the end breathing a mix that is feeding me a partial pressure of O2 of 1.6 ATM.

It seems like even more of a potential benefit to CCR divers, where one of their most significant risks is breathing a way-too-high partial pressure of oxygen, as a result of some kind of malfunction or operator error.