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Saturated Fat
@judy yeah I wanted to say "except eskymos" Of course there are fat animals, but in general most people living in the forests or tropical jungles would hunt lean animals and their diet is far from high fat diet.
"That is why marathon runners do better on a ketogenic diet. A runner using carbs for energy will "bonk" or hit the wall after the glycogen is used up and must get refueled with "energy drinks" on route to keep going. One using ketones can run until they have depleted all their body fat, which is not likely to happen."
If you think that the best marathon runners from Africa are on keto diets and during races don't use gels than obviously you have no idea about any of this.. Marathon runners from Africa are on high carb diets potatoes, corn, rice and other starches. They will not "bonk" because when you are trained in aerobic exercise like they are. You are able to use much bigger ratio of body fat to glycogen for energy than regular people and because marathons are fast you can't run without using gels. Only some ultra marathon runners are on keto diets. But it's more like fast walking not crazy fast running like during marathon.. This shows me that you don't do your own research. You just say what low carb promoters will say.. Same with Navy Seals yeah you hear about this method with ketones for divers. But they are not in ketosis doing their operations LOL. THey are on power bars and gatorade drinks all day. Listened and watched thousand of hours of podcasts and videos that are now available on the interner about Navy Seals and their wokr.. Btw there you have some videos about diet of best marathon runners.
Quote from tim on January 26, 2022, 6:34 pmI'm not wrong. This is elementary physiology.
The mammalian brain depends on glucose as its main source of energy. In the adult brain, neurons have the highest energy demand [1], requiring continuous delivery of glucose from blood. In humans, the brain accounts for ~2% of the body weight, but it consumes ~20% of glucose-derived energy making it the main consumer of glucose (~5.6 mg glucose per 100 g human brain tissue per minute [2]).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3900881/
Glucose is the only fuel normally used by brain cells. Because neurons cannot store glucose, they depend on the bloodstream to deliver a constant supply of this fuel. Fatty acids do not serve as fuel for the brain, because they are bound to albumin in plasma and so do not traverse the blood-brain barrier. In starvation, ketone bodies generated by the liver partly replace glucose as fuel for the brain. (Biochemistry. 5th edition.Berg JM, Tymoczko JL, Stryer L.)
https://biology.stackexchange.com/questions/34159/why-is-the-brain-dependent-on-glucose
Glucose, a form of sugar, is the primary source of energy for every cell in the body. Because the brain is so rich in nerve cells, or neurons, it is the most energy-demanding organ, using one-half of all the sugar energy in the body.
Brain functions such as thinking, memory, and learning are closely linked to glucose levels and how efficiently the brain uses this fuel source. If there isn’t enough glucose in the brain, for example, neurotransmitters, the brain’s chemical messengers, are not produced and communication between neurons breaks down. In addition, hypoglycemia, a common complication of diabetes caused by low glucose levels in the blood, can lead to loss of energy for brain function and is linked to poor attention and cognitive function.
“The brain is dependent on sugar as its main fuel,” says Vera Novak, MD, PhD, an HMS associate professor of medicine at Beth Israel Deaconess Medical Center. “It cannot be without it.”
https://hms.harvard.edu/news-events/publications-archive/brain/sugar-brain
None of your sources say anything about cellular substrate preference when both ketones and glucose are abundantly supplied. You don't have to be in a "state of ketosis" to have a lot of ketones in the blood. You could instead eat coconut oil or palm kernel oil, or take the isolated MCTs from these oils, or take other ketone supplements. You can achieve 0.5 nmol/L just from eating coconut oil, and you can get to 3.0 with certain ketone supplements. In any of these scenarios, when both glucose and ketones are supplied, the cells that are capable of burning ketones will preferentially do so (meaning they burn ketones first and then when the ketones are gone they switch over to glucose)
@judy you said "The reason the diet helps is because it produces fewer waste products that they have to get rid of. I witnessed this first hand when my husband had a cardiac arrest from low Potassium caused by blood pressure medicine."
I just read your story on your website. How is your husband doing now? Has he been able to get off all his meds?
Quote from Judy on January 25, 2022, 5:43 pmWe are equipped for survival. We eat carbs when they are available because it provokes insulin, which puts it into storage in the fat cells where it can be used when the carbs (fruit and plant foods) are gone. The body tries hard to protect its precious fat stores because that is its emergency stash, therefore the carbs get burned until they are gone and then it switches to burning fat. We now live in an endless summer with abundant food and we never need to use up our reserve energy. Clearly a recipe for obesity. Ketones from saturated fat gives us a way to game the system by satisfying our hunger without making us fat.
Salt: why do you think ketosis is not a preferred state? It takes a few more calories to use gluconeogenesis to make the small amount of necessary glucose, but when has burning a few more calories ever been a negative?
Because gluconeogenesis is driven by adrenaline and cortisol, the glucocorticoids. These are the hormones that trigger gluconeogenesis, they always rise when blood sugar gets below a certain level, to instruct the body to create more sugar. People who are in ketosis have chronically elevated cortisol levels by about 25-40%. However some people seem to do absolutely fine with ketosis despite this, if it works for you then I wouldn't at all advice you to do anything else. There might be many factors affecting how much these elevated stress hormones affects a person, genetic and environmental
No. In fact the brain is quite resistant to using ketones. Even after a few days of ketosis the brain will only be getting about a quarter of its energy from ketones. It takes close to a month of ketosis for the brain to switch to using 60% ketones. So no, during glycolysis the brain does not use ketones even if they are available.
Quote from tim on January 27, 2022, 8:32 amNo. In fact the brain is quite resistant to using ketones. Even after a few days of ketosis the brain will only be getting about a quarter of its energy from ketones. It takes close to a month of ketosis for the brain to switch to using 60% ketones. So no, during glycolysis the brain does not use ketones even if they are available.
You are just wrong, and you can't ever admit being wrong about anything. It does take some time for ketone use to reach maximum utilization but that is not the question we were discussing.
Quote from kathy55wood on January 27, 2022, 7:23 am@judy you said "The reason the diet helps is because it produces fewer waste products that they have to get rid of. I witnessed this first hand when my husband had a cardiac arrest from low Potassium caused by blood pressure medicine."
I just read your story on your website. How is your husband doing now? Has he been able to get off all his meds?
It's been about 5 years now and my husband is doing great for his age! The only negative thing that happened to him as a result of his ordeal is that he came home from the hospital about an inch shorter than when he went in. It was probably because he had 12 broken ribs and they kept him sitting up (slumped over) in the hospital and when he came home he had a terrible cough from all the tubes down his throat. He had to sleep sitting up (also slumped over) for about 2 months. He didn't notice he was shorter until he put on a tie and his old system of measuring where to put the knot by his shirt buttons didn't work.
As to the meds, he got off 2 of them very quickly but is still on way too many IMO. I also didn't think he needed the pacemaker, which is why he has to take blood thinners to prevent clots. Every time they check his pacemaker they find that he has not used up any of the battery life. It was supposed to last 10 years and now they say he still has 10 years left on it. However, it would probably be more trouble to remove it than it leave it in.
Thank your for your inquiry! I am grateful every day for our good fortune.
Quote from tim on January 27, 2022, 8:32 amNo. In fact the brain is quite resistant to using ketones. Even after a few days of ketosis the brain will only be getting about a quarter of its energy from ketones. It takes close to a month of ketosis for the brain to switch to using 60% ketones. So no, during glycolysis the brain does not use ketones even if they are available.
What we want is to be metabolically flexible, i.e., able to switch to using whatever energy source is available. I suspect that is why Africans are the best runners. It could be an adaptation after thousands of years of hunting by running their prey to exhaustion. (The animals overheat because they are covered with fur, while humans are "naked apes.") Drs. Stephan Phinney and Jeff Volek did a lot of research on the subject. I recommend their book, The Art and Science of Low Carbohydrate... book by Jeff S. Volek (thriftbooks.com)
We often use the terms ketogenic and low-carb interchangeably, but you are right that it takes a while to be totally in ketosis. I try to do intermittent fasting by eating in a fairly short window and extending the overnight fast. This seems to work well for most people.
Projecting because you've been proven wrong isn't a good look.
It's absolutely relevant. It takes time for brain cells to keto adapt in ketosis meaning they aren't even using ketones in glycolysis, never mind preferentially. Your claim that brain cells prefer ketones over glucose is totally wrong and you've backed it up with no good reasoning or evidence because you can't.