Considered a symptom of the keto flu, your breath on this diet often smells fruity at first. This is because acetone is a by-product of ketosis and is eliminated mostly through the lungs and the breath, according to a study in the journal International Journal of Environmental Research and Public Health in February 2014. Acetone is a type of ketone known for having a fruity aroma in smaller concentrations. “It’s hard to say exactly how long it will last as it depends on the person, but it’s common for someone to experience this side effect for a few weeks,” says Asche.
Children who discontinue the diet after achieving seizure freedom have about a 20% risk of seizures returning. The length of time until recurrence is highly variable, but averages two years. This risk of recurrence compares with 10% for resective surgery (where part of the brain is removed) and 30–50% for anticonvulsant therapy. Of those who have a recurrence, just over half can regain freedom from seizures either with anticonvulsants or by returning to the ketogenic diet. Recurrence is more likely if, despite seizure freedom, an electroencephalogram shows epileptiform spikes, which indicate epileptic activity in the brain but are below the level that will cause a seizure. Recurrence is also likely if an MRI scan shows focal abnormalities (for example, as in children with tuberous sclerosis). Such children may remain on the diet longer than average, and children with tuberous sclerosis who achieve seizure freedom could remain on the ketogenic diet indefinitely.[46]
These are the widely recognized LCT’s, or long chain fatty acids in coconut oil, mostly saturated, including stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (18:2). The exact percentage of each depends on region the coconut is grown, time of harvest, and other growing variables. They are good as a fuel source in your food, and have some of the tastiness of coconut oil, if your goal is getting into ketosis fast, you won’t benefit from eating a lot more of them compared to eating true medium chain fatty acids.
The thing is, for keto to work, it can’t just be treated like any other diet, which is really confusing considering all the pundits touting the “keto diet.” Eating a balanced diet in daylight hours and night capping with a “keto bar” from Whole Foods is not going to put you in a state of ketosis, nor is eating keto religiously and bingeing the family sized bag of Doritos twice a week. Putting the word “diet” beside “keto” is a bit misleading because it downplays the outrageous restrictions required to put your body in an unnatural fat-burning state. In order to accomplish the “ketosis” most diet plans talk about, you need to radically change your lifestyle -- and, unlike switching to a balanced diet of whole foods, you must be fairly religious about carb restriction in order to reap the benefits.
Let’s talk about a keto side effect that may not be so sexy: constipation. “Many of the richest sources of fiber, like beans, fruit, and whole grains are restricted on the ketogenic diet,” says Clark. “As a result, ketogenic eaters miss out on the benefits of fiber-rich diet such as regular laxation and microbiome support. The microbiome has been implicated in everything from immune function to mental health.” Indeed, in a long-term study in the Journal of Pediatrics in April 2015, constipation was noted as a very common side effect in children receiving ketogenic diets for epilepsy treatment.
"The keto diet is primarily used to help reduce the frequency of epileptic seizures in children. While it also has been tried for weight loss, only short-term results have been studied, and the results have been mixed. We don't know if it works in the long term, nor whether it's safe," warns registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital.

When you order here, you get 1560g unflavored Glycofuse – 3.4 pound with zero nasty additives or artificial sweeteners, at only 100 calories per serving. Just pure, clean-burning highly branched cluster dextrin for that slow bleed of carbohydrates you need to support energy for a long workout or race, or for the glycogen replenishment you need after a tough day at the gym, without getting massive fluctuations in blood sugar. 

“When you start the keto diet, you lose sodium and other electrolytes in the urine due to reductions in insulin,” says Yawitz. “This is a major contributor to symptoms of keto flu.” So it’s important to replenish sodium through the diet, especially if you exercise or sweat a lot. “This can help ward off more serious side effects that are seen with long-term sodium deficiencies,” says Yawitz. These include lethargy and confusion — and in extreme cases, seizures, coma, and death, according to the Mayo Clinic.

A high-fat diet also trains your body to burn even more fat during exercise, even at high intensities. Fat is released faster and in greater amounts from your storage adipose tissue and transported more quickly into your muscles and mitochondria. Your muscles also store more energy as fat and use this fat-based fuel more efficiently and quickly. Even more interestingly, a high-fat diet can cause a shift in the gene expression that codes for specific proteins that increase fat metabolism – and create very similar adaptations to exercise itself. So the mere act of shifting primary fuel intake from carbohydrates to fat begins to make you more “fit”, even if you’re not exercising.
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
What a great post. I thought i would add about the selection of food you eat on keto and that everyone is different. Some food gives you energy and some doesnt, this varies person to person. I started and quit keto 3 times before i managed to find my balance. The first few times it made be poorly, from the shock of diet change. However, you can wean yourself into the diet which i did the last time when i had the most success.
BHB is the primary ketone your body can most efficiently use as fuel during exercise and at rest (especially when you’re keto-adapted), it is the most stable of the ketones, and it is actually found in nature in many foods including eggs and milk. A “BHB salt” is simply a compound that consists of sodium (Na+), potassium (K+), and the ketone body beta-hydroxybutyrate.
Two years after my first oatmeal binge, I found myself in an All Ages and Genders eating disorder support group, sandwiched between a bulimic father/bodybuilder and a teenage girl who had to drop out of high school for inpatient treatment. We would sit around and discuss incentives to eat normally, such as “I don’t want to die of osteoporosis” and “I’d like to have a friend or two sometime in the future” and “I want to enjoy a croissant again.” Together we relearned how to eat, because we had a new and sustainable goal -- we wanted to live a life without shame and obsession.
And it’s not an easy diet to stick to, even in the short term. Fell pointed me to a series of articles he’d written after talking to scientists about low-carb diets. As a former track runner myself, I wasn’t surprised to hear him say that carb depletion is terrible for athletes, nor did it come as a shock to hear that fat isn’t necessarily going to make you feel “fuller for longer.”
It also means that if you’re a very active athlete or exercise enthusiast and you’re following “trickle-down” advice from the sedentary or less active ketosis experts to eat less than 40g of carbs per day, you’re making a big mistake when it comes to your hormonal balance, and you need to up your carbohydrate intake to 100-200g of carbs per day. You’d be surprised at how easy it is (if you’re a very active person) to stay in ketosis on this level of carbohydrate intake. Go ahead. Do Ketonix breath testing to prove me wrong. You can eat boatloads of carbohydrates at night and be back in ketosis within just two to three hours. When you combine that with the cutting-edge tricks you’re about to learn, you’ll find that you can toss hormonal issues out the window, get into ketosis, have your cake, and eat it too. Literally.
A systematic review in 2018 looked at 16 studies on the ketogenic diet in adults. It concluded that the treatment was becoming more popular for that group of patients, that the efficacy in adults was similar to children, the side effects relatively mild. However, many patients gave up with the diet, for various reasons, and the quality of evidence inferior to studies on children. Health issues include high levels of low-density lipoprotein, high total cholesterol, and weight loss.[24]
I don’t know about you, but I find these risks pretty damn concerning. The fact is that I want to be around to play with my grandkids, and considering that my genetic testing with 23andMe has revealed that I have a higher-than-normal risk for type 2 diabetes, I doubt that shoving more gooey gels and sugary sports drinks into my pie hole is going to do my health any favors. So if I can achieve similar levels of performance and body composition with carbohydrate restriction, I’m all in.
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]
Whether ketosis is taking place can be checked by using special urine test strips such as Ketostix. The strips have a small pad on the end, which the user dips in a fresh urine specimen. Within seconds, the strip changes color to indicate the level of acetoacetate ketone bodies, which reflects the degree of ketonuria, which, in turn, gives a rough estimate of the level of hyperketonemia in the body (see table below). Alternatively, some products targeted to diabetics such as the Abbott Precision Xtra or the Nova Max can be used to take a blood sample and measure the β-hydroxybutyrate ketone levels directly. Normal serum reference ranges for ketone bodies are 0.5–3.0 mg/dL, equivalent to 0.05–0.29 mmol/L.[29]
The nerve impulse is characterised by a great influx of sodium ions through channels in the neuron's cell membrane followed by an efflux of potassium ions through other channels. The neuron is unable to fire again for a short time (known as the refractory period), which is mediated by another potassium channel. The flow through these ion channels is governed by a "gate" which is opened by either a voltage change or a chemical messenger known as a ligand (such as a neurotransmitter). These channels are another target for anticonvulsant drugs.[7]
Meat – like grass-fed selections – and fresh veggies are more expensive than most processed or fast foods. What you spend on Keto-friendly foods will vary with your choices of protein source and quality. You can select less-expensive, leaner cuts of meat and fatten them up with some oil. Buying less-exotic, in-season veggies will help keep you within budget.
Might not be nutritional. Could be a training issue. Could be fascial. Could be neurotransmitter. If you're taking 1 serving of UCAN perhaps you need two. Not sure of ht, body wt, etc. 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.
There are theoretically no restrictions on where the ketogenic diet might be used, and it can cost less than modern anticonvulsants. However, fasting and dietary changes are affected by religious and cultural issues. A culture where food is often prepared by grandparents or hired help means more people must be educated about the diet. When families dine together, sharing the same meal, it can be difficult to separate the child's meal. In many countries, food labelling is not mandatory so calculating the proportions of fat, protein and carbohydrate is difficult. In some countries, it may be hard to find sugar-free forms of medicines and supplements, to purchase an accurate electronic scale, or to afford MCT oils.[54]
If you’re following the keto diet, you will need protein, but you should limit your intake to about 20 percent of your total daily calories. (1) This is important because when you consume more protein than you need, your body converts the excess protein into carbs through a process called gluconeogenesis. This process pushes your body out of ketosis.
I was shocked at how easy it was (using the new supplements and methods outlined below that have been developed since my initial foray into ketosis) to get into ketosis without extreme carbohydrate restriction, without excessive, diarrhea and “diaper-moment” inducing amounts of MCT and coconut oil, and without the inflammation, triglyceride and hormonal issues, or social discomfort I outline above. I was also able to achieve a much more immediate and deeper level of ketosis than I ever achieved in previous experiments sans these newer strategies you’re going to learn about.

"Some people stop working with me because they're not going to be proven wrong. You’re dissing their religion," said Libby, a registered dietician who asked that her full name not be used because of the private hate messages she's received from the community.   “If there was a diet or a pill or something that really was this miracle diet weight-loss thing that lasted and was healthy for you, we wouldn't have all these different diets all the time, there wouldn't be health complications, there wouldn't be so much controversy about it and the first time that you'd be learning about it wouldn't be on a 3pm talk show."


Checking your ketone level is one way to know if you’re in ketosis. This metabolic state usually kicks in after three or four days of restricting your carbohydrate intake or going through periods of intermittent fasting. You don’t have to visit a doctor to measure your level. Pick up a ketone urine test from a nearby drug store, or use a blood sugar meter that’s capable of measuring ketones.

High levels of circulating ketones may have a direct appetite-suppressant effect. In fact, the exogenous ketone ester used in HVMN Ketone rapidly increased blood levels of beta-hydroxybutyrate and lowered appetite as well as levels of ghrelin - the hormone that increases hunger. While this still needs to be explored further, it is possible that exogenous ketones may be useful for appetite control as part of a holistic weight loss strategy.11 


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”.


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.
Acetyl-CoA can be metabolized through the TCA in any cell, but it can also undergo a different process in liver cells: ketogenesis, which produces ketone bodies.[27] Ketone bodies are also produced in mitochondria, and usually occur in response to low blood glucose levels.[28] When glucose levels are low, oxaloacetate is diverted away from the TCA cycle and is instead used to produce glucose de novo (gluconeogenesis). But when oxaloacetate is unavailable to condense with acetyl-CoA, acetyl-CoA cannot enter the cycle, and so the body has evolved an alternative way to harvest energy from it.
For anyone, regardless of any underlying health issues, the so-called keto flu is a possibility (and even likelihood) as your body adjusts to ketosis on the keto diet, says Tori Schmitt, RDN, founder of YES! Nutrition, LLC based in Dayton, Ohio. Fatigue, irritability, headaches, and nausea are all symptoms of the keto flu, Schmitt says. Fortunately, keto flu lasts only about one to two weeks.

In many developing countries, the ketogenic diet is expensive because dairy fats and meat are more expensive than grain, fruit and vegetables. The modified Atkins diet has been proposed as a lower-cost alternative for those countries; the slightly more expensive food bill can be offset by a reduction in pharmaceutical costs if the diet is successful. The modified Atkins diet is less complex to explain and prepare and requires less support from a dietitian.[55]
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!
It usually takes three to four days for your body to go into ketosis because you have to use up your body's stores of glucose, i.e., sugar first, Keatley says. Any major diet change can give you some, uh, issues, and Keatley says he often sees patients who complain of IBS-like symptoms and feeling wiped out at the beginning of the diet. (The tiredness happens because you have less access to carbs, which give you quick energy, he explains.)
I am not a doctor and this is not to be taken, interpreted or construed as medical advice. If you have poor liver or gallbladder function, it can be a good idea to take care of that prior to a high fat diet, yes. But a healthy high fat diet would not cause liver issues per se. These are just my own personal thoughts and not a prescription or a diagnosis or any form of health care whatsoever.
Ken, not 100% sure I understand your question but if you're asking if you should take any more supplements through out the week, it's hard to know without getting some blood testing done. If you want to go into detail, book a consult at bengreenfieldfitness.com/coaching and choose 20 or 60 mins and we'll get you scheduled. If you want to know specifically about fueling for your runs, have a read through this: https://bengreenfieldfitness.com/2013/07/what-…

Endogenous ketone production denotes ketones produced naturally by the body. It's the body’s natural adjustment to the absence or restriction of carbohydrate in the diet. Without enough glucose from carbs to fuel its cells, the body turns to fat to replace glucose as its primary source of energy. In the liver, fat that is not burned for energy directly is converted to ketones. This means that you are in a ketogenic state. Ketone levels increase in the bloodstream and provide an alternate and efficient fuel source for the body and brain. As a result, muscle protein is spared from being converted to glucose for energy.
After reading the article I shopped around and I noticed there are types of MCT oil that are derived from Palm Oil and are considerably less expensive. (http://prototypenutrition.com/keto8.html ) There is a litany of research that says that Palm Oil is on the same level a High Fructose Corn Syrup when it comes to your body. Is this true for MCT oil made from Palm Oil? Is Coconut derived superior to Palm Oil or a blend of the two?
As insulin levels plummet from carb-cutting, more water is flushed out, along with excess sodium (in contrast, excess insulin from carbs causes sodium and water retention).4 In some people, dehydration contributes to constipation, which can also result from avoiding fiber-rich carbohydrate foods. While less common, diarrhea or loose bowels can be triggered by a number of factors including too much or too little fat, dairy intolerance, or changes in gut flora. 

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!


MCT oil is extracted primarily from coconut oil, and derives unique benefits from its shorter fatty acid chain length. Most dietary fat contains 12 carbons in the fatty acid chain, while MCTs are only 6 - 12 carbon chains in length. Shorter chain length allows for easier absorption and rapid conversion to energy in the liver, specifically caprylic (C8) and capric (C10).
“Rapid, significant weight loss is a common side effect of the keto diet because of the water losses that occur as carbohydrate stores are depleted,” says Clark. In a study in the American Journal of Clinical Nutrition, obese men following a modified version of the ketogenic diet, with high protein and low carbs, lost about 14 pounds in one month, compared with the control group, which lost about 10 pounds on a high-protein, medium-carb diet.
Peak fat oxidation was 2.3-fold higher in the LC group (1.54 ± 0.18 vs 0.67 ± 0.14 g/min; P = 0.000) and it occurred at a higher percentage of VO2max (70.3 ± 6.3 vs 54.9 ± 7.8%; P = 0.000). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21 ± 0.02 vs 0.76 ± 0.11 g/min; P = 0.000) corresponding to a greater relative contribution of fat (88 ± 2 vs 56 ± 8%; P = 0.000). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180 min of running (−64% from pre-exercise) and 120 min of recovery (−36% from pre-exercise).
The ketogenic diet achieved national media exposure in the US in October 1994, when NBC's Dateline television programme reported the case of Charlie Abrahams, son of Hollywood producer Jim Abrahams. The two-year-old suffered from epilepsy that had remained uncontrolled by mainstream and alternative therapies. Abrahams discovered a reference to the ketogenic diet in an epilepsy guide for parents and brought Charlie to John M. Freeman at Johns Hopkins Hospital, which had continued to offer the therapy. Under the diet, Charlie's epilepsy was rapidly controlled and his developmental progress resumed. This inspired Abrahams to create the Charlie Foundation to promote the diet and fund research.[10] A multicentre prospective study began in 1994, the results were presented to the American Epilepsy Society in 1996 and were published[17] in 1998. There followed an explosion of scientific interest in the diet. In 1997, Abrahams produced a TV movie, ...First Do No Harm, starring Meryl Streep, in which a young boy's intractable epilepsy is successfully treated by the ketogenic diet.[1]

The Gatorade Sports Science Institute (GSSI) is widely considered one of the world’s top go-to resources for cutting-edge exercise and nutrition science advice – which is probably why Gatorade vending machines dot the campus here, and the majority of the kids seem to be walking around campus with a never-ending big gulp-sized cup full of sports drink.


A survey in 2005 of 88 paediatric neurologists in the US found that 36% regularly prescribed the diet after three or more drugs had failed, 24% occasionally prescribed the diet as a last resort, 24% had only prescribed the diet in a few rare cases, and 16% had never prescribed the diet. Several possible explanations exist for this gap between evidence and clinical practice.[34] One major factor may be the lack of adequately trained dietitians, who are needed to administer a ketogenic diet programme.[31]

Basically, the proven science is in the pudding. A highly cited low-carb study from The New England Journal of Medicine concludes with the statement, “The low-carbohydrate diet produced a greater weight loss (absolute difference, approximately 4 percent) than did the conventional diet for the first six months, but the differences were not significant at one year.” The study mentions health benefits from the low carb diet, of course, but that it’s largely unsustainable.
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The thing is, for keto to work, it can’t just be treated like any other diet, which is really confusing considering all the pundits touting the “keto diet.” Eating a balanced diet in daylight hours and night capping with a “keto bar” from Whole Foods is not going to put you in a state of ketosis, nor is eating keto religiously and bingeing the family sized bag of Doritos twice a week. Putting the word “diet” beside “keto” is a bit misleading because it downplays the outrageous restrictions required to put your body in an unnatural fat-burning state. In order to accomplish the “ketosis” most diet plans talk about, you need to radically change your lifestyle -- and, unlike switching to a balanced diet of whole foods, you must be fairly religious about carb restriction in order to reap the benefits.
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