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The first modern study of fasting as a treatment for epilepsy was in France in 1911.[12] Twenty epilepsy patients of all ages were "detoxified" by consuming a low-calorie vegetarian diet, combined with periods of fasting and purging. Two benefited enormously, but most failed to maintain compliance with the imposed restrictions. The diet improved the patients' mental capabilities, in contrast to their medication, potassium bromide, which dulled the mind.[13]
Ketone bodies are acidic, but acid-base homeostasis in the blood is normally maintained through bicarbonate buffering, respiratory compensation to vary the amount of CO2 in the bloodstream, hydrogen ion absorption by tissue proteins and bone, and renal compensation through increased excretion of dihydrogen phosphate and ammonium ions.[9] Prolonged excess of ketone bodies can overwhelm normal compensatory mechanisms, defined as acidosis if blood pH falls below 7.35.
The ketogenic diet reduces seizure frequency by more than 50% in half of the patients who try it and by more than 90% in a third of patients.[18] Three-quarters of children who respond do so within two weeks, though experts recommend a trial of at least three months before assuming it has been ineffective.[9] Children with refractory epilepsy are more likely to benefit from the ketogenic diet than from trying another anticonvulsant drug.[1] Some evidence indicates that adolescents and adults may also benefit from the diet.[9]
If you remain under your optimal net carbs limit, then you should enter ketosis within 2 to 3 days. But it can take up to 7 days. The fastest way to get into ketosis is to exercise on an empty stomach, in order to accelerate the depletion of glycogen in your body. You can also do a Fat Fast for a few days (eating more fat) to speed up the rate at which you enter ketosis AND start to cut out refined carbs (like sugar) before you go for full ketosis. Another option is to do a water fast, (only drinking water) which also speeds up getting into ketosis.
You need to do a “common man’s” version of a good ketogenic nutrition program or discussion. Great article, and I leaned a few things. Those Ketone Salts and other supplements can get pricey. I eat a very low carb and high fat diet and meander in and out of ketosis during the week. A pure ketogenic diet is so restrictive that meals it can get very repetitive during the week. I’d like to learn more about cooking with oils and how temperature effects their qualities. I can only handle eating so much raw food, and I love to cook my greens and other vegetables in bacon fat and coconut oil. It will be next May before I can get my blood work performed (insurance reasons) so until then I’ll need to be careful and hold back on those after supper dark chocolate excursions! Thanks!!
Hi Ben – Great article. I had trouble at the end figuring out if you were now eating high fat (60-80% of calories), or if you went back to something closer to 50% fat calories and higher carbs and are using exogenous ketones to get int ketosis when needed. Are you doing any carbs at night or a refeed, or just having higher carbs on most days? Thanks
Frankly, the results of my foray into ketosis and eventually keto-adaptation were astounding. I had the best Ironman triathlon season of my life and shocking levels of mental focus and physical ease, especially for races and workouts that lasted longer than two hours. Without experiencing muscle loss, hunger pangs or brain fog, I found I could go the entire day without eating, which was enormously helpful for business and personal productivity. My gas, bloating, fermentation and GI “issues” disappeared. My blood levels of inflammatory markers like HS-CRP and cytokines dropped to rock-bottom, while my levels of good cholesterol, vitamin D, and anti-inflammatory fatty acids skyrocketed.
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A study with an intent-to-treat prospective design was published in 1998 by a team from the Johns Hopkins Hospital[20] and followed-up by a report published in 2001.[21] As with most studies of the ketogenic diet, no control group (patients who did not receive the treatment) was used. The study enrolled 150 children. After three months, 83% of them were still on the diet, 26% had experienced a good reduction in seizures, 31% had had an excellent reduction, and 3% were seizure-free.[Note 7] At 12 months, 55% were still on the diet, 23% had a good response, 20% had an excellent response, and 7% were seizure-free. Those who had discontinued the diet by this stage did so because it was ineffective, too restrictive, or due to illness, and most of those who remained were benefiting from it. The percentage of those still on the diet at two, three, and four years was 39%, 20%, and 12%, respectively. During this period, the most common reason for discontinuing the diet was because the children had become seizure-free or significantly better. At four years, 16% of the original 150 children had a good reduction in seizure frequency, 14% had an excellent reduction, and 13% were seizure-free, though these figures include many who were no longer on the diet. Those remaining on the diet after this duration were typically not seizure-free, but had had an excellent response.[21][22]


Because the ketogenic diet alters the body's metabolism, it is a first-line therapy in children with certain congenital metabolic diseases such as pyruvate dehydrogenase (E1) deficiency and glucose transporter 1 deficiency syndrome,[35] which prevent the body from using carbohydrates as fuel, leading to a dependency on ketone bodies. The ketogenic diet is beneficial in treating the seizures and some other symptoms in these diseases and is an absolute indication.[36] However, it is absolutely contraindicated in the treatment of other diseases such as pyruvate carboxylase deficiency, porphyria, and other rare genetic disorders of fat metabolism.[9] Persons with a disorder of fatty acid oxidation are unable to metabolise fatty acids, which replace carbohydrates as the major energy source on the diet. On the ketogenic diet, their bodies would consume their own protein stores for fuel, leading to ketoacidosis, and eventually coma and death.[37]
A Cochrane systematic review in 2018 found and analysed eleven randomized controlled trials of ketogenic diet in people with epilepsy for whom drugs failed to control their seizures.[2] Six of the trials compared a group assigned to a ketogenic diet with a group not assigned to one. The other trials compared types of diets or ways of introducing them to make them more tolerable.[2] In the largest trial of the ketogenic diet with a non-diet control[16], nearly 38% of the children and young people had half or fewer seizures with the diet compared 6% with the group not assigned to the diet. Two large trials of the Modified Atkins Diet compared to a non-diet control had similar results, with over 50% of children having half or fewer seizures with the diet compared to around 10% in the control group.[2]

“Studies have shown that the ability to stick to a diet is more important for long-term success than the type of diet that’s followed,” says Yawitz. “Keto is incredibly restrictive and is particularly tough for those who have frequent social engagements or are prone to carb cravings.” The Mediterranean diet allows you to eat carbs, like as many fruits and veggies as you want, along with whole grains. Not to mention, the Mediterranean diet has been linked to a number of other health benefits, including a lower risk of Alzheimer’s and Parkinson’s disease, certain types of cancer, and heart disease, according to the Mayo Clinic.
But beyond that, experts aren't convinced that the keto diet has any other scientifically-proven health benefits. In fact, it may have some distinct downsides. If you follow the keto diet incorrectly, for example (like by eating lots of saturated fats, versus healthy unsaturated fats), you're at risk of raising your cholesterol levels. “The best strategy to keep your heart healthy is to get as much fat as possible from unsaturated sources such as olive, avocado and canola oils, nuts, seeds, avocados, and olives," says Ansel.

Ketone bodies are acidic, but acid-base homeostasis in the blood is normally maintained through bicarbonate buffering, respiratory compensation to vary the amount of CO2 in the bloodstream, hydrogen ion absorption by tissue proteins and bone, and renal compensation through increased excretion of dihydrogen phosphate and ammonium ions.[9] Prolonged excess of ketone bodies can overwhelm normal compensatory mechanisms, defined as acidosis if blood pH falls below 7.35.
As a matter of fact, it’s more dangerous to have high levels of cholesterol and high levels of CRP than low levels of cholesterol and high levels of CRP – even if your high levels of cholesterol are “healthy”, big fluffy LDL particles, and not small, dense vLDL particles. In other words, no matter how many healthy fats you’re eating, these fats may actually come back to bite you if you’re creating high inflammation from too much exercise, not enough sleep, exposure to toxins and pollutants, or a high-stress lifestyle.
You state that many athletes and very active people could benefit from 100-200g of carbs a day, and be back in ketosis in a few hours. Any particulars on which kind of activities or say how long/many training sessions would benefit from this to balance hormones. I train mma 3-4 days a week and also do lots of hiit and strength training as well. Just trying to see if this is a situation where i would benefit from your suggestions. Thanks!
The concentration of ketone bodies may vary depending on diet, exercise, degree of metabolic adaptation and genetic factors. Ketosis can be induced when a ketogenic diet is followed for more than 3 days.[34] This induced ketosis is sometimes called nutritional ketosis.[35] This table shows the concentrations typically seen under different conditions[1]
As a matter of fact, from a pure biology perspective, lauric acid should actually be considered a LCT, because unlike C8 and C10 forms of MCT, lauric acid gets processed by your liver. This matters because your body metabolizes MCT’s differently than LCT’s: unlike LCT’s, MCT’s get very quickly converted into ketone energy to fuel your brain and body instead of requiring a pit stop in the liver for processing.
Another difference between older and newer studies is that the type of patients treated with the ketogenic diet has changed over time. When first developed and used, the ketogenic diet was not a treatment of last resort; in contrast, the children in modern studies have already tried and failed a number of anticonvulsant drugs, so may be assumed to have more difficult-to-treat epilepsy. Early and modern studies also differ because the treatment protocol has changed. In older protocols, the diet was initiated with a prolonged fast, designed to lose 5–10% body weight, and heavily restricted the calorie intake. Concerns over child health and growth led to a relaxation of the diet's restrictions.[19] Fluid restriction was once a feature of the diet, but this led to increased risk of constipation and kidney stones, and is no longer considered beneficial.[18]
And what I’m writing has nothing to do with taking supplements to induce ketosis or whatever. I believe these things are covered in Volek & Phoney’s book The Art and Science of Low Carb Living, which I would have thought you to be very familiar with. The iodine stuff you can read about in Iodine, Why We Need, Why We Can’t Live Without It by Brownstein.
Some research suggests that ketogenic diets might help lower your risk of heart disease. Other studies show specific very-low-carb diets help people with metabolic syndrome, insulin resistance, and type 2 diabetes. Researchers are also studying the effects of these diets on acne, cancer, polycystic ovary syndrome (PCOS), and nervous system diseases like Alzheimer's, Parkinson's, and Lou Gehrig's disease.

What would your advice be to a high raw vegan who wants to try an HRV keto diet? The supps you recommended above look vegan, but aren’t the results based on those of omnis? Would they work the same way on vegans? Also I heard you mention in the recent Keto Summit that SE Asians need a little more carb and I happen to be one. I’m a petite 39-YO female and I’ve been raw for the past 11 years. I have been practicing intermittent fasting in the last 7 years and try to eat only twice a day. Up to how many grams of carbs can I consume to get into ketosis?
Cyclical keto diet: The Bulletproof Diet falls into this category. You eat high fat, low carb (less than 50 grams of net carbs a day) five to six days of the week. On day seven, you up your carb intake to roughly 150 grams, during what’s called a carb refeed day. Carb cycling this way helps you avoid the negative effects some people experience when they restrict carbs long term, like thyroid issues, fatigue and dry eyes.[9][10]  Learn more here about how carb cycling works.
Awesome… I am a newbie to this i took the keto os for 2 months for weight loss and did well. It a bit pricey. I try hard to conform to lchf diet daily but see no change other than I crave sweets. In 5’7 270 and stuck! My highest weight was 390 had gastric band put in 10 years ago but its just keep me from consumption of large amounts at on time. Is there a more economical way to stay in ketosis? I wAnt more energy… In not an exercise person usually have no energy. In willing to try other ideas.
Here are a few of the most common side effects that I come across when people first start keto. Frequently the issues relate to dehydration or lack of micronutrients (vitamins) in the body. Make sure that you’re drinking enough water (close to a gallon a day) and eating foods with good sources of micronutrients. To read more on micronutrients, click here >
I think there is a lot more to the story than ketosis or very low carb for everyone. In my own experience, high carb works much better. I tried very low carb for a long without really feeling amazing, I then switched back to high carb and quickly lost weight and leaned out. I still eat high carb and my strength is better and I'm even leaner now. I find it very difficult to overeat (I obviously eat very 'clean diet').

Following the ketogenic diet and achieving ketosis may be beneficial if you’re living with type 2 diabetes and need to manage your symptoms. Limiting carbohydrate intake is crucial with type 2 diabetes because too many carbs can increase blood glucose levels, which can damage blood vessels and lead to vision problems, kidney problems, and nerve problems.
The ketogenic diet typically reduces carbohydrate intake to less than 50 grams per day — and calls for increased protein and fat intake, according to a review published in August 2013 in the European Journal of Clinical Nutrition. Roughly speaking, on keto you’ll get 70 to 80 percent of your calories from fat, about 20 percent from protein, and as little as 5 percent from carbs.
Other causes of diarrhea on the keto diet include consuming a diet low in fiber (fiber helps ward off diarrhea by bulking up stool) and eating processed low-carb foods like shakes and bars that may contain sugar alcohols. These sugar alcohols can ferment in the gut and cause gastrointestinal discomfort. Yawitz suggests limiting foods labeled “sugar free” if you’re prone to gas or diarrhea when you eat them. And you may want to gradually adjust your carbs downward and your fats upward. “Also build your diet around [naturally] high-fiber, low-carb foods like avocado and nonstarchy vegetables such as broccoli, cauliflower, and asparagus,” she says. Other keto-friendly ways to get more fiber include chia seeds, almonds, and coconut.
So which MCT to pick? Brain Octane (pure C8) provides the fastest rise in ketones and burns the cleanest, with minimal gut irritation. XCT oil is more affordable but works more slowly with less direct cognitive effects. The capric acid C10 in XCT Oil doesn’t break down into ketones as quickly as pure caprylic C8, but capric acid C10 is more affordable, so you can save money by going with the XCT oil. XCT oil still goes to brain energy, just not as quickly as Brain Octane. Both can be used for energy without processing by the liver, unlike many other fats and oils.
The Dr. Formulated Keto line of products is fully transparent, compliant to the keto guidelines and designed to be convenient—we’ve done the math for you—just mix. Crafted for those seeking to enter into ketosis or stick to a low-carbohydrate diet for weight loss and health purposes, all Dr. Formulated products are Keto Certified, Paleo Friendly and clean: Non-GMO Project Verified and Truly Grass Fed.
For example, in trained people and athletes who eat a low-carbohydrate, high-fat diet (not to be confused with a low-carbohydrate, high-protein diet), a large amount of fat burning can take place at intensities well above 80 percent maximum oxygen utilization (VO2 max) – allowing for very-high-intensity or long efforts with low calorie intake and also allowing for use of fat fuel stores during long steady-state exercise, even at a relatively fast pace (so much for the “fat burning zone” giving you the best bang for your buck). With high-fat, low-carb intake, you can go hard and still burn tons of fat. In addition, this means that more carbohydrate stores will be available when you really need them, such as for an all-out, 100%, maximum effort.
Alison Moodie is a health reporter based in Los Angeles. She has written for numerous outlets including Newsweek, Agence France-Presse, The Daily Mail and HuffPost. For years she covered sustainable business for The Guardian. She holds a master’s degree from Columbia University’s Graduate School of Journalism, where she majored in TV news. When she's not working she's doting on her two kids and whipping up Bulletproof-inspired dishes in her kitchen.
Similar to the BHB salts and MCT’s from the KETO//OS I discuss above, powdered forms of ketones are excellent if you don’t want to completely eliminate carbohydrates or protein (which can be gluconeogenic when eaten in excess) or eat copious amounts of fats, but want to simultaneously maintain high levels of blood ketones. It may also be used to ease the transition into a ketogenic state, because it can help alleviate the fatigue and lethargy some  people experience while making the transition from a glucose metabolism (carb burning mode) to ketone metabolism (fat burning mode).
Note: Are you a vegetarian or vegan and want to go on a ketogenic diet? It’s still possible! Just keep in mind that the dietary restrictions can sometimes be a little bit intense. Make sure to plan ahead and prepare to aid your success. To help out, we’ve published articles (with 7 day meal plans included) for both the vegetarian ketogenic diet and the vegan ketogenic diet.

Hi Ben, I have a question about being in ketosis. So from what I understand, a serving of Keto os will keep you in ketosis for about 4-6 hours or so……my question is doesn’t your body have to be in constant ketosis in order to really experience the benefits of using the fat as fuel? Also, if someone is not following the Keto diet, what happens to the glucose they are still consuming if they are supposedly using ketones for energy? Also, do you see any benefit from using Keto os vs. Brain Octane? I ask because there is a significant difference in price. Thank you so much!!
First, decide if you need to check ketones.  Amy Berger of Tuit Nutrition has a great post here to help you decide.  If, after reading that, you still want to check your ketone levels, there are several ways to check them. You can buy Bayer ketone stix, and check the levels of ketones in your urine. Or you can use a blood ketone meter.  The Precision Xtra has been the one to use until just recently. The problem is that this meter is hard to find, as the manufacturer Abbott keeps changing the name. The strips are even harder to find and buy.
Wow! Amazing article. I don’t read blogs regularly, but I’ll be reading more of yours. I am on day 11 of a fast to get me into ketosis; 7 days bone broth and now on day-4 water only. Intentions are weight loss (10# down, 15# more to go) and immunity improvement/gut help. Planning 9 days of whey water, fermented veggies and mad probiotics when the water days are done (day 14?). After this fast I want to stay fat adapted, start training again and get down to 8% body fat. I believe you have cut that journey significantly with this article. Thank you.
Selecting the right food will be easier as you become accustomed to the Keto approach. Instead of lean meats, you’ll focus on skin-on poultry, fattier parts like chicken thighs, rib-eye steaks, grass-fed ground beef, fattier fish like salmon, beef brisket or pork shoulder, and bacon. Leafy greens such as spinach, kale and lettuce, along with broccoli, cauliflower and cucumbers, make healthy vegetable choices (but you’ll avoid starchy root foods like carrots, potatoes, turnips and parsnips). You can work in less-familiar veggies such as kohlrabi or daikon.

Typically, to gain lean body mass one needs to have some degree of caloric surplus, or at the very least, not be in a significant deficit. This is especially true when looking to add muscle mass. It is certainly possible to gain muscle mass on a ketogenic diet. For most individuals this would require consuming adequate protein (while still remaining in ketosis), enough calories to support growth, sufficient electrolytes to support muscle function, as well as incorporating progressive resistance training. The type and volume of resistance exercise needed to add lean body mass will be very dependent on the individual and their age, training status, health status, etc. Therefore, the answer to this question can become quite nuanced, but in simple terms, yes, it is very possible to gain lean body mass on a ketogenic diet while still taking advantage of the health promoting effects this way of eating provides.
Once inside the mitochondrion, the dominant way that the bound fatty acids are used as fuel in cells is through β-oxidation, which cleaves two carbons off of the acyl-CoA molecule in every cycle to form acetyl-CoA.[24] Acetyl-CoA enters the citric acid cycle, where it undergoes an aldol condensation with oxaloacetate to form citric acid; citric acid then enters the tricarboxylic acid cycle (TCA), which harvests a very high energy yield per carbon in the original fatty acid.[25][26]
But wait, there’s one loophole. Have polycystic ovary syndrome (PCOS)? Then the keto diet may help regulate your periods. “Women with PCOS have high insulin levels, which cause sex hormone imbalances,” notes Yawitz. In a small study published in the journal Nutrition & Metabolism, subjects with PCOS following a ketogenic diet for six months noted improvements in their menstrual cycles — and a small number of women became pregnant, overcoming previous infertility obstacles. “This study was very small, so we can’t make recommendations for all women with PCOS based on its findings,” says Yawitz. “And really, any diet that leads to weight loss should help in PCOS.”
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