I see a lot of people say that ketosis is great for insulin sensitivity. BUT, in my experience ketosis causes physiological insulin resistance whereby the muscles and liver are sparing glucose for the brain. Hence, glucose tolerance actually goes down during ketosis. As such, is it possible that post workout carbs could do a lot more damage than they would on a non-ketogenic diet? Or maybe, as Kiefer suggests, glucose uptake post workout is not moderated by insulin at all i.e. muscles soak up glucose regardless of their insulin sensitivity? Or maybe cyclical ketosis doesn’t allow liver glycogen to get low enough to trigger physiological insulin resistance?
The ketogenic diet has been studied in at least 14 rodent animal models of seizures. It is protective in many of these models and has a different protection profile than any known anticonvulsant. Conversely, fenofibrate, not used clinically as an antiepileptic, exhibits experimental anticonvulsant properties in adult rats comparable to the ketogenic diet.[58] This, together with studies showing its efficacy in patients who have failed to achieve seizure control on half a dozen drugs, suggests a unique mechanism of action.[56]

Weight loss benefits ushered the keto diet into the spotlight. That’s how most people have likely heard about ketones, a fuel source created naturally by the body when burning fat. But more and more research points to diverse applications of ketones in the blood outside of just fat loss, from improved endurance performance to the treatment of medical conditions like epilepsy.


Long-term use of the ketogenic diet in children increases the risk of slowed or stunted growth, bone fractures, and kidney stones.[18] The diet reduces levels of insulin-like growth factor 1, which is important for childhood growth. Like many anticonvulsant drugs, the ketogenic diet has an adverse effect on bone health. Many factors may be involved such as acidosis and suppressed growth hormone.[38] About one in 20 children on the ketogenic diet develop kidney stones (compared with one in several thousand for the general population). A class of anticonvulsants known as carbonic anhydrase inhibitors (topiramate, zonisamide) are known to increase the risk of kidney stones, but the combination of these anticonvulsants and the ketogenic diet does not appear to elevate the risk above that of the diet alone.[39] The stones are treatable and do not justify discontinuation of the diet.[39] Johns Hopkins Hospital now gives oral potassium citrate supplements to all ketogenic diet patients, resulting in one-seventh of the incidence of kidney stones.[40] However, this empiric usage has not been tested in a prospective controlled trial.[9] Kidney stone formation (nephrolithiasis) is associated with the diet for four reasons:[39]

I'd recommend starting with glucose and hemoglobin A1C, along with a good multi like https://bengreenfieldfitness.com/multi and a fish oil like the one at greenfieldfitnesssystems.com – Anyways, I'd be happy to help you via a personal one-on-one consult. Just go to https://bengreenfieldfitness.com/coaching. and then choose a 20 or 60 minute consult, whichever you'd prefer. I can schedule ASAP after you get that.
In other words, I personally found that while following “strict ketosis”, things became eerily similar to the days in college when I was a competitive bodybuilder pursuing sub-3% body fat percentages. I simply wasn’t the most fun guy to hang out with in social situations due to my extreme dietary restrictions, the intense self-control became nearly exhausting, and when I traveled, I missed out on many culinary experiences, such as homemade ravioli in Rome, freshly baked crostinis in the Basque regions of Spain, and Korean rice bowls in Seoul.
I’ve been experimenting with MCT Oil Brain Octane. I have one questions. I’ve been eating about 20 – 25 gr. of carbs per day on a high fat, medium protein diet. I’m measuring ketones in the morning before taking the MCT and after. I’ve been taking btw. 1-2 tbsp of MCT Brain Octane with butter (Bulletproof coffee) – I measure again after 30 min., 1hr, 2 hrs. and don’t see a raise in my blood ketones. Anything I’m missing, would love to hear your thoughts, Ben. – Thx I’m measuring with Precision Xtra and Ketonix Red.

Putting — and then keeping — your body in ketosis isn’t exactly easy. You’ll need to severely minimize your intake of carbohydrates, eating no more than 20 to 50 grams (g) of carbs per day to get there and stay there. A single medium pear, for example, contains 26 g of carbs, and even foods that aren’t generally considered high in carbs — such as nuts and nonstarchy veggies — contain a small amount of carbohydrates, and so will need to be limited or avoided on this plan.

After increasing water intake and replacing electrolytes, it should relieve most all symptoms of Keto Flu. For an average person that is starting a ketogenic diet, eating 20-30g of net carbs a day, the entire adaptation process will take about 4-5 days. My advice is to cut your carbs to fewer than 15g to ensure that you are well on your way into ketosis within one week. If you are experiencing any more keto flu symptoms, double check your electrolyte intake and adjust.
On the keto diet, your body begins to shed fat, water and glycogen, and as this happens you lose key electrolytes, such as sodium, potassium and magnesium. When you're running low on these electrolytes, you might experience headaches or extreme fatigue. These losses are most pronounced during the first few weeks after you enter ketosis, so if you're going to start the keto diet it's best to plan ahead to make sure you get healthy amounts of these electrolytes — and other vitamins and minerals — either through supplements or a thoughtfully-designed meal plan.
There are numerous benefits that come with being on keto: from weight loss and increased energy levels to therapeutic medical applications. Most anyone can safely benefit from eating a low-carb, high-fat diet. Below, you’ll find a short list of the benefits you can receive from a ketogenic diet. For a more comprehensive list, you can also read our in-depth article here >
Now open your eyes. Unfortunately, you still have the same amount of self-control as you before. Your roommate still wants to get margaritas and tacos next week. Butter still doesn’t taste good in coffee. Small-smilers on public transport are almost never going to say anything to you. The ketogenic diet is an empty promise, propagandized by brainwashed influencers and companies that want to profit from you. There’s no need to meditate on what being keto actually looks like -- just observe closely as the people around you, without apprehension, recreate their world based on diet blog listicles and tell you that you should, too -- until they realize the myth and quit and say nothing about it.
Note that urine measurements may not reflect blood concentrations. Urine concentrations are lower with greater hydration, and after adaptation to a ketogenic diet the amount lost in the urine may drop while the metabolism remains ketotic. Most urine strips only measure acetoacetate, while when ketosis is more severe the predominant ketone body is β-hydroxybutyrate.[36] Unlike glucose, ketones are excreted into urine at any blood level. Ketoacidosis is a metabolic derangement that cannot occur in a healthy individual who can produce insulin, and should not be confused with physiologic ketosis.

Early studies reported high success rates; in one study in 1925, 60% of patients became seizure-free, and another 35% of patients had a 50% reduction in seizure frequency. These studies generally examined a cohort of patients recently treated by the physician (a retrospective study) and selected patients who had successfully maintained the dietary restrictions. However, these studies are difficult to compare to modern trials. One reason is that these older trials suffered from selection bias, as they excluded patients who were unable to start or maintain the diet and thereby selected from patients who would generate better results. In an attempt to control for this bias, modern study design prefers a prospective cohort (the patients in the study are chosen before therapy begins) in which the results are presented for all patients regardless of whether they started or completed the treatment (known as intent-to-treat analysis).[19]
People seem to expect, based on fitness guru promises, that being in a state of ketosis feels like a cognition-enhancing, energy-stimulating power hour whereby your waist measurement is negatively correlated with your IQ. I usually just felt fatigued as hell if I tried to exercise, beating my body to death on an aged and grating stair climber at 6am. Then I went about the day eating random assortments of protein and fat, felt totally out of control at the sight of brownies in the office, overdid coffee to suppress my cravings and increase my metabolism, and went to bed feeling the dull ache of deprivation underneath my dieting high. And that was only the beginning.
While it is believed that carbohydrate intake after exercise is the most effective way of replacing depleted glycogen stores,[72][73] studies have shown that, after a period of 2–4 weeks of adaptation, physical endurance (as opposed to physical intensity) is unaffected by ketosis, as long as the diet contains high amounts of fat, relative to carbohydrates.[74] Some clinicians refer to this period of keto-adaptation as the "Schwatka imperative" after Frederick Schwatka, the explorer who first identified the transition period from glucose-adaptation to keto-adaptation.[75]
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Hi, I’m still a bit skeptical, I have seen some of my friends do the keto diet, and have had good results. Though I am still not sure about the idea of the fats being eaten. They say they eat meat with the fat and must do so, is this correct? Also isn’t this not good for the body especially for the kidneys? Second, can a diabetic do this diet? There are many questions running through my head.

Reduced hunger. Many people experience a marked reduction in hunger on a keto diet. This may be caused by an increased ability of the body to be fueled by its fat stores. Many people feel great when they eat just once or twice a day, and may automatically end up doing a form of intermittent fasting. This saves time and money, while also speeding up weight loss.
The day before admission to hospital, the proportion of carbohydrate in the diet may be decreased and the patient begins fasting after his or her evening meal.[19] On admission, only calorie- and caffeine-free fluids[37] are allowed until dinner, which consists of "eggnog"[Note 8] restricted to one-third of the typical calories for a meal. The following breakfast and lunch are similar, and on the second day, the "eggnog" dinner is increased to two-thirds of a typical meal's caloric content. By the third day, dinner contains the full calorie quota and is a standard ketogenic meal (not "eggnog"). After a ketogenic breakfast on the fourth day, the patient is discharged. Where possible, the patient's current medicines are changed to carbohydrate-free formulations.[19]

Over 8–10 mmol/l: It’s normally impossible to get to this level just by eating a keto diet. It means that something is wrong. The most common cause by far is type 1 diabetes, with severe lack of insulin. Symptoms include feeling very sick with nausea, vomiting, abdominal pain and confusion. The possible end result, ketoacidosis, may be fatal and requires immediate medical care. Learn more
It seems like everyone is talking about the keto diet — the high-fat, low-carb eating plan that promises to turn your body into a fat-burning machine. For that reason, keto has surged in popularity over the past year as a lose-weight-fast strategy. Thank Hollywood A-listers and professional athletes like Halle Berry, Adriana Lima, and Tim Tebow who’ve publicly touted the diet’s benefits, from shedding weight to slowing down aging. Here’s everything you need to know about going keto.

On the ketogenic diet I feel very shaky/anxious from when I wake up til about noon. Eating doesn’t really help. It could be electrolyte related but seems possibly more related to excess cortisol/adrenaline as noon is also when I start to crash and get tired on a more normal diet, and because those 3 am awakenings that worsen simultaneously in ketosis seem to also have to do with HPA axis stuff. Does this side effect potentially also have to do with my fasting blood sugar being elevated?
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?
Apparently, Dominic’s research seems to be suggesting the fact that diet-induced ketosis from a high-fat, low-carb intake, especially when combined with the use of nutrition supplements such as powdered ketones or MCT oil, can vastly reduce the need for the brain to use oxygen to burn glucose. This is because the brain can use up to around 75% of its fuel from ketones. So a ketone-fed or a fat-adapted brain can be better equipped to withstand low oxygen availability and potentially support longer breath-hold times. Dominic’s research also shows that in the presence of ketosis, the brain and body are able to resist the potential cell damage of long periods of time with low oxygen, also known as “hypoperfusion”.
Hi Ben, great article. I have been a keto-adapted athlete for over 2 years, all through nutrition (65/25/10). I have recently discovered UCAN, KetoOS and MAP Aminos. So, here’s my question: If I am going out for a 4-hour ride, and I want to fuel myself just on these supplements and my body’s natural fat stores, how and in what order should I take them? If I take them all together, will the aminos in the KetoOS interfere with MAP Aminos? Or should I just make a mix of the UCAN and KetoOS in 10oz of water and use it to wash back my 6 MAP tablets, 15-mins before my ride? Thanks for your advice!

Hello, may I ask if someone has some experience week fasting for 14 days? I was told that the food which should be started taken after 14 days of fasting has to be in very simple and in slow amount. Unfortunately 1-2 days after fasting I am allowed to take only bouillon out of buckwheat, barley, from the 3rd day buckwheat mush, and only from 5th day milk or sour cream, oil since 11th day. Can anyone advice how should I adopt this come back food path to Ketogenic diet? Thank you in advance, Maria
This answer made me sad. Having lived in New York all of my life, I from a young age saw loved ones fall victim to spontaneous gluten intolerance and restaurants run to their rescue with accommodating menus.  This is why I get annoyed. What’s a dietary prescription for someone who wants to go to a dinner party and be able to eat a meal that was prepared for them? Keto is cultish not for its members’ radical commitment to a dietary restriction but for their lack of full participation in the outside world.
Don’t fall for it. The keto fad will perish and be replaced by another miracle diet, and another and another, each with a different set of promises that are similar in that they are empty.  Believe me, there exist human beings without killer metabolisms that are still able to eat the foods they enjoy while maintaining a healthy weight. In fact, the reason they are healthy physically is because they’ve chosen not to kid themselves in terms of what is sustainable for them, and instead choose to keep active, toss the Wonder bread, and get in touch their bodies in a way that allows them to eat intuitively. As someone who used to believe this could never, ever be possible for me, I promise that it’s more than possible for you -- it’s essential.

I am curious if someone takes any or too much MCT oil (5-10 tablespoons/day) or Exogenous Ketones will the liver slow/stall or shut off endogenous ketone production as you are providing the ketones exogenously and thereby you may NEED to supplement ketones to maintain ketone levels or you may suffer a short term ketone deficit while the liver adjusts to making them on its own again. A parallel I am thinking of is exogenous testosterone supplementation and the hypothalamus/endocrine system slowing/stopping endogenous testosterone production (seen in bodybuilders).
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.”
“Certainly, the quality of fat counts,” says Yawitz. “There’s a big difference nutritionally between bacon and almonds. As much as possible, people set on the keto diet should emphasize plant-based, unsaturated fats like nuts, seeds, olive oil, and avocado, which have even been shown to protect the heart.” If you have high cholesterol or other risk factors for heart disease, you should speak with your doctor before beginning the keto diet. This is because the diet may — but doesn't have to — include large amounts of saturated fat. Some studies have shown increases in cholesterol and triglycerides in people following the diet, while other research reveals that the keto diet may actually decrease heart disease risk as well as saturated fat intake.
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