> your body closely regulates the level of glucose in your blood. Your brain would literally starve without it.
Is this actually true? Having done the ketogenic diet and bringing carbohydrates down to almost nothing, my brain definitely didn't starve. In fact, running on ketones was amazing.
It kinda depends on what exactly they mean. Is it true that if you had zero glucose available in your bloodstream at all
your brain would be unable to function? Yes. Is it true that if nothing you ate contained any glucose your brain would starve? No. There's a process called gluconeogenesis which produces more than enough glucose for your brain to function no matter how few carbs you eat.
The amount of carbohydrates you need in your diet to survive is exactly zero. They’re a non-essential macronutrient.
The amount of glucose you need in your blood stream to keep everything running smoothly is a very small amount easily produced by your body through a process called gluconeogenesis.
I went 60 days sans any calories and my body self regulated glucose just fine.
I went 21 days with just water and electrolytes. My son is a type 1 diabetic so I had access to a glucose meter to test myself with. My blood glucose level at about the halfway mark was 59mg/dL (for reference, most non-diabetics should be between 70-130.)
I won't say fasting for 21 days was the most pleasant experience, but it is entirely doable by the average healthy person. Nice job going 60 days. The hardest part for me was the social aspect, family/friends' repeated concerns because I'm 'starving myself', sitting at the dinner table while everyone else eats, etc.
Do you mind sharing some of the side-effects you experienced as well as your goal overall for the 21 day fast? Mostly curious about weight/mass loss numbers but also any adverse bodily reactions.
For the first 2-3 days I was hungry - after that I was fine.
For the remainder:
I felt tired, cranky, cold (especially at night), and on occasion I would have trouble getting to sleep. My inflammation was markedly decreased. I have dermatographia (skin writing) where I can use my fingernail to draw a line on my arm (for example) and within a couple of minutes it will swell up like an allergic reaction. After about 5 minutes it goes away. I tried doing this halfway into my fast and while the inflammation was still there, it was much much much less noticeable (and not puffed up.)
As far as overall goal, aside from losing some weight was trying to reset my immune system which has been out of sorts for the past couple of years. I've been through a battery of tests to figure out why I've been feeling less than normal (brain fog, neuropathy, etc.) for the past 2-3 years and I was hoping it would help. Alas it did not. I lost 31lb and gained about half of it back after a couple of months. I wasn't following any particular diet after the fast, particularly because when I experience these bouts of brain fog/malaise, I don't feel motivated to stay on track.
I've started walking 5-7 miles a day and exercising over the past couple of months and have noticed some improvement. I did a 3 day water fast a few weeks ago, who knows if that was a factor. I'm maybe 85% of the old me, which is a massive improvement from where I was coming from. Hopefully things continue to improve (or simply doesn't get worse.)
I only got glucose/ketone strips around day 35 of the 60. Lowest I recorded was around 50mg/dL, highest was 110mg/dL, with the average being around 75mg/dL or so.
Ketones were always at or near the limit the meter is designed to test for. I think anything over 8.0 mmol/L and it would yell at me to see a doctor. Lowest I recorded was 7.0, and almost every reading was over 8.0. Felt fine the whole time.
Echo what you said about the hardest part being social though.
Eliminating carbohydrates from your diet means eliminating vegetables from your diet. I'm highly skeptical of the claim that any such diet can ever be healthy in the medium to long term. I fail to see how malnourishment isn't a certainty under such circumstances.
The fact that humans can fast for weeks or months isn't evidence in favor of:
> The amount of carbohydrates you need in your diet to survive is exactly zero.
> Two normal men volunteered to live solely on meat for one year, which gave us an unusual opportunity of studying the effects of this diet. The term “meat,” as used by us, included both the lean and the fat portions of animals. The subjects derived most of their calories from fat and the diet was quite different from what one, who uses the term “meat” as including chiefly lean muscle, would expect.
...
> 11. In these trained subjects, the clinical observations and laboratory studies gave no evidence that any ill effects had occurred from the prolonged use of the exclusive meat diet.
People in the Arctic circle like the Inuit always lived almost entirely off of meat and Mongolians and other steppe pastoralists come very close, adding dairy.
> The mortality from all cardiovascular diseases combined is not lower among the Inuit than in white comparison populations. If the mortality from IHD is low, it seems not to be associated with a low prevalence of general atherosclerosis. A decreasing trend in mortality from IHD in Inuit populations undergoing rapid westernization supports the need for a critical rethinking of cardiovascular epidemiology among the Inuit and the role of a marine diet in this population.
> Most studies found that the Greenland Eskimos and the Canadian and Alaskan Inuit have CAD as often as the non-Eskimo populations. Notably, Bang and Dyerberg's studies from the 1970s did not investigate the prevalence of CAD in this population; however, their reports are still routinely cited as evidence for the cardioprotective effect of the "Eskimo diet."
They don't have lower incidence of ischemic heart disease than white westerners, they don't have lower levels of atherosclerosis, and these have actually improved as their diets have become more western and less traditional.
> I'm highly skeptical of the claim that any such diet can ever be healthy in the medium to long term. I fail to see how malnourishment isn't a certainty under such circumstances.
No malnourishment in the linked study or in Inuit populations.
> Inuit populations suffering lower incidence of heart disease is a myth.
I never claimed they did. I was responding to your claim that you don’t see how a long term all meat diet can be healthy and that malnourishment is certain with an all meat diet. If the Inuit incidence of cardiovascular disease is not lower I presume it’s also not higher or it’d have been mentioned.
The claim was not that an all meat diet was healthier, but that it was roughly as healthy. If their incidence ischemic heart disease and atherosclerosis is no lower than white westerners but they don’t get diabetes because they don’t eat carbs that’s (incredibly weak) evidence of health benefits.
Again, I’m not saying the diet is healthier, I’m showing evidence that it is healthy in the long run and that malnourishment is not a certainty.
Vitamin and other supplements could probably close the gap? Vegans do this when they lack certain vitamins largely/only present in animal products and I don't see why the opposite can't be true.
It's not a gap, it's an absence, and the deficiencies incurred by eating zero fruits and vegetables are not analogous to a b-12 deficiency (which most meat eaters also suffer, just to a lesser extent than vegans). These deficiencies aren't going to be made up for in pill form. Not to mention consuming no fruits and vegetables means you are essentially on a very low fiber diet, which has huge health implications on its own and is probably a bad idea.
This is a lot of work to go to in order to hang on to a pet diet that is shown to cause arterial injury and doesn't lead to greater weight loss than less harmful diets.
Yep. Lost 80 lbs in 2 months. Got a few e-mails about this comment already so I'm throwing together a quick summary of what I did, results, and logs I took during the fast. Learned a lot since that fast though, it was over two years ago at this point.
Eating is definitely optional if you have the body fat.
In the other thread you mentioned strict "no flavored anything". Can you elaborate why not?
In my case I tend to feel less hungry after drinking lots of flavored water (e.g., lemon juice or flavored electrolyte powder [1]), but I haven't yet done long fasting. I want to try soon.
Also, have you noticed any cognitive decline when you were fasting for weeks? Difficulty concentrating, memory loss, lightheadedness, mood, ability to interact with people?
Some unflavored sweeteners have been shown to produce mild insulin responses. For me it was more of a psychological thing, especially on a fast that long.
And no, no cognitive decline whatsoever. If anything I had more energy. Also, I was supplementing electrolytes, and I ended my fast at like 25% bodyfat though, so keep that in mind.
I looked at his comment history and found 37 weeks ago that he says he only drank water and salt the first 30 days and added supplements the last 30 so I'm pretty sure he meant no calories. I also don't think that is a world record by any means. I found this site where someone they cite a 1972 NIH study of someone who fasted for 382 days but evidently I can't paste in this android client. Hunger strikes have definitely gone on for longer than 60 days. Water is essential but the body can subsist for a lot longer without food.
One negative experience, slight hair loss that started approximately 6 to 8 weeks post fast. Maybe 10 to 15% of the hair on my head fell out in total, but it all grew back.
One other negative experience but that was due to my own stupidity and I've since learned better.
Basically if you're above 15% bodyfat, you only need two things to live. Water and electrolytes.
If anyone has any questions, more than happy to answer e-mails.
Hey man just wanted to say you inspired me to give fasting a try. Not going to go crazy, don't worry, just shooting for two or three days depending on how it goes (just hit 24 hrs). I'm doing lots of research and have my annual check up in a couple weeks to talk to my doc about a longer one.
Same thing that gets everyone on a fast, too much water, not enough electrolytes.
Essentially got really really bad cramps in my legs each morning towards the end of the first 30 days. Fixed itself as soon as I added in the magnesium and potassium supplements. Likely caused because I drank too much water during the early parts of the fast.
Interesting! So salt, Magnesium, and potassium only. I want to try fasting for a week or so. Is there a specific type of these supplements you recommend?
After the first two weeks, it was a mild background noise. I never even felt ravenous or anything, just 'Eh, it'd be nice to eat again'. Even at the end I felt like I could have gone another 30 days easily. Which, given that I ended my fast at around 25% bodyfat, I probably could have.
Why? Spinach isn’t even close to as bad as people like to make it out to be. For me it ranges from a nice lettuce replacement to something that doesn’t really alter the flavour of what it’s mixed with. Sure, if you cook it with stuff it turns all mushy, so I guess most people actually don’t like the texture more than the flavour itself.
In the diet you describe the body would preferentially reserve all glucose for the brain and run the rest on ketones. The body can manufacture glucose when needed from other energy sources but it’s an energy intensive biochemical process and not ideal for efficient use of available nutrients.
Always happy to find out new understandings of physiology and biochemistry so I dove back into some research this morning after seeing your comment.
The brain does use ketones in starvation sitautions, but it always needs to use some glucose, so over time the available glucose ends up redirected there.
From what I can find it appears that the heart does utilize ketone bodies for fuel, contrary to what you are asserting. There is correlation to heart failure, possibly from stress in utilizing an energy source with less efficient bioavailability.
We are down to anecdotal evidences here. So as another anecdote, a guy I know went on a carb-free diet and developed diabetes as a result. His body lost the ability to process sugar.
Bottom line, most people needs a balanced diet - including carbs that are one of the pillars of nutrition. A given individual's body may be able to compensate for the imbalance on its own, but let's not generalize that to the entire population.
your hypothesis seems to be that a lack of carbohydrates (read: sugar) caused an individual to develop diabetes, but "diabetes" generalizes down to:
- the body (pancreas) does not produced insulin at all (type I)
- the body's cells are resistant to the produced insulin (type II)
we should be able to basically rule out type II because there should have largely been no insulin produced by this individual (glucagon would take priority due to low blood sugar), so insulin resistance seems super unlikely. and type I has a mix of factors but they are largely all autoimmune, where various pancreatic cells are destroyed by the body itself, causes generally unknown.
"losing the ability to process sugar" seems really sketchy, because those are all critical cellular processes that don't just go away. i realize you're probably not biologically trained but that statement doesn't make a whole lot of sense.
so which form of diabetes did this individual get diagnosed with?
> "losing the ability to process sugar" seems really sketchy, because those are all critical cellular processes that don't just go away.
I have no idea as to the validity of this anecdote but the idea isn't unprecedented. For example, correcting an iodine deficiency can cause the same thyroid issues that a deficiency can cause.
The main difference there is that processing sugar is absolutely vital to the functioning of a cell. If you'd actually lose the ability to process sugar there is no amount of insulin that will save you from death.
They're simply not, the body can manufacture all the glucose it needs.
The ketogenic diet is glucose sparing, that is your insulin levels are dramatically lowered since the very small amount of glucose you're eating should go to the tissues that require it, not into your fat cells.
So if you're on a ketogenic diet and then eat a lot of glucose, your body takes a little while to ramp back up insulin. That's not the same thing as insulin resistance or impaired insulin production in diabetics.
Your brain would starve without glucose, but your body can produce the glucose your brain needs, so it’s not something that would ever happen. But the statement is still technically correct.
This statement isn't supported by any real evidence. In fact, a lot of actual research supports the idea of keto for improving outcomes in some types of cancer.
Ketogenic diets limit protein too, since your body can process protein and turn it into glucose. I don't know what you're talking about when you say excess given its a high fat, low protein, and very low carbohydrate diet.
When did Youtube videos started to be reference source ? I can't find any academic references on her work despite her putting "Ph.D" title after her name on every plateform existing.
Is this actually true? Having done the ketogenic diet and bringing carbohydrates down to almost nothing, my brain definitely didn't starve. In fact, running on ketones was amazing.