" "

The bottom line is that there have not been enough scientific studies, especially longer term ones, to really determine all the potential risks and benefits of the keto diet. Many of the claims out there on the Internet, social media, or television in either direction are anecdotal, meaning that they are individuals telling stories about what has supposedly been their experiences. Take everything you hear that is not supported by scientific evidence with a grain of salt (but not too much salt because too much can be bad for you.)
I was thinking of buying exogenous ketones for my mother. She plays golf daily but gained some weight as of late. My mother does not want to do the diet but I was thinking this might help her with energy and losing weight. Another person told me it would help her. But then I got to thinking, if she went into Ketosis, then wouldn’t she get the keto flu rather than get energy and mental clarity? Would I need to tell her to take it everyday?
Great article! As someone who just started a “ketogenic diet” two weeks ago, I am opting to hold off on using ketone supplements for the following reason. You state how “Keto-adaptation occurs when you have shifted your metabolism to relying on fat-based sources, instead of glucose (sugar) sources, as your primary source of fuel.” If the goal is to “switch” our body’s energy supply to ketones and one uses supplemental ketones, how do they really ever know if their body has successfully accomplished this goal if they are using supplemental ketones? Aren’t they getting a false sense of ketosis if their blood or breath tests show them above 0.5 millimolar through the use of the supplements? I understand that it may take me longer to reach ketosis naturally but I guess I see it was worth it to truly reap all of the benefits that you outline in your article.
The longer cholesterol circulates in your bloodstream, the higher the likelihood that it will dig its way into an endothelial wall and potentially contribute to atherosclerosis or plaque formation. This is why it’s so dangerous to eat a high-fat diet, but to also have your nightly dark chocolate bar, overdo it on the red wine, or have weekly “cheat days” with pizza, pasta, or sugar-laden ice cream.
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]

Yes, they're technically a fruit, but we think olives deserve a shout-out all of their own, since they're also a great source of healthy fats and are one of a few keto-approved packaged foods. Plus, they're a great source of antioxidants, will satisfy your craving for something salty, and are blissfully low-carb. “About a palm's worth only has 3 grams of net carbs,” Sarah Jadin, RD, told Health in a previous interview.
It seems strange that a diet that calls for more fat can raise “good” cholesterol and lower “bad” cholesterol, but ketogenic diets are linked to just that. It may be because the lower levels of insulin that result from these diets can stop your body from making more cholesterol. That means you’re less likely to have high blood pressure, hardened arteries, heart failure, and other heart conditions. It's unclear, however; how long these effects last.
Perhaps you fall into the category of Olympic athletes who would dope with damaging drugs, even if they knew it would kill them. However, if you desire a long, high-quality life, you don’t want to be a washed up ex-exerciser with diabetes, or you don’t want to experience joint, nerve and brain inflammation, damage and degradation, you may need to adjust your lens.
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]
The keto diet changes the way your body converts food into energy. Eating a lot of fat and very few carbs puts you in ketosis, a metabolic state where your body burns fat instead of carbs for fuel. When your body is unable to get glucose from carbs, your liver converts fatty acids from your diet into ketones, an alternative source of energy. Burning ketones in place of glucose reduces inflammation and spurs weight loss.[1]
The popular low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come with the same risks if you overdo it on fats and proteins and lay off the carbs. So why do people follow the diets? "They're everywhere, and people hear anecdotally that they work," McManus says. Theories about short-term low-carb diet success include lower appetite because fat burns slower than carbs. "But again, we don't know about the long term," she says. "And eating a restrictive diet, no matter what the plan, is difficult to sustain. Once you resume a normal diet, the weight will likely return."
For patients who benefit, half achieve a seizure reduction within five days (if the diet starts with an initial fast of one to two days), three-quarters achieve a reduction within two weeks, and 90% achieve a reduction within 23 days. If the diet does not begin with a fast, the time for half of the patients to achieve an improvement is longer (two weeks), but the long-term seizure reduction rates are unaffected.[44] Parents are encouraged to persist with the diet for at least three months before any final consideration is made regarding efficacy.[9]
I would do breath ketone measurements. That's exactly what I do and this is what I use :https://greenfieldfitnesssystems.com/product/ketonix-breath-ketone-monitor/
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.

Eat fewer calories by lowering your fat intake. On keto, protein and carb intake is usually the same for everyone, but you may want to adjust your fat intake to eat fewer calories than you're eating now. Because keto has a metabolic advantage over other weight-loss diets, you may only need to reduce your calories slightly (around 300 kcal less a day).


This article is excellent and I’ve actually read it a few times just to make sure I’m absorbing as much as possible. With that said can we talk a bit about protein? Why does it seem like protein is taking a back seat? What about the athlete who needs to maintain and/or increase muscle mass. I don’t want to make any assumptions and with all the research I’ve done along with personal testing into Keto it just seems to me that protein and its benefits are not a discussion point in this diet. Why?

For example, a key component of safe and lasting fat loss is your capability to tap into your body’s own storage fat for energy. This access to fat cannot happen if your body is constantly drawing on carbohydrate reserves and blood glucose for energy. In the type of moderate- to high-carbohydrate diets you’ve learned are widely recommended by prevailing nutrition science, not only does the utilization of fat for energy become far less crucial (since you’re constantly dumping readily available sugar sources into your body), but your metabolism never becomes efficient at using fat. There is a growing body of evidence proving that a high-fat, low-carbohydrate diet results in faster and more permanent weight loss than a low-fat diet. Furthermore, appetite satiety and dietary satisfaction significantly improve with a high-fat, low-carbohydrate diet that includes moderate protein.
Keto-adaptation, AKA “becoming a fat burning machine”, occurs when you have shifted your metabolism to relying on fat-based sources, instead of glucose (sugar) sources, as your primary source of fuel. Your body increases fat oxidation, and breaks down fats into ketones to be used as the primary energy source. Depending on your current level of carbohydrate intake (takes longer if you’re pretty sugar addicted), this process can take two weeks to six months to fully train your body to, but once done, it’s done, and you have achieved fat-burning status that can stick with you for life.
the abnormal accumulation of ketones in the body as a result of excessive breakdown of fats caused by a deficiency or inadequate use of carbohydrates. Fatty acids are metabolized instead, and the end products, ketones, begin to accumulate. This condition is seen in starvation, occasionally in pregnancy if the intake of protein and carbohydrates is inadequate, and most frequently in diabetes mellitus. It is characterized by ketonuria, loss of potassium in the urine, and a fruity odor of acetone on the breath. Untreated, ketosis may progress to ketoacidosis, coma, and death. See also diabetes mellitus, ketoacidosis, starvation. ketotic, adj.
Humans have always relied on ketones for energy when glucose sources were scarce (i.e. no fruits available during winter). It is a normal state of metabolism. In fact, most babies are born in a state of ketosis. However, with abundant sources of carbohydrate, people rarely access ketosis and it becomes a dormant metabolic pathway.Our ancestors likely had frequent periods of time when high carbohydrate food wasn’t immediately available. For this reason, our bodies are amazing at adapting to burning of ketones for fuel.
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.
You indicate that exogenous ketones do not shut down the ability, of your body, to oxidize fat. Is that to say it does not have an effect on your body at all? My specific question is… does my body oxidize less fat, when supplementing with exogenous ketones? I think you indicate in your article that it could. I would expect it to, in that if I supplement then my body would not “need” to oxidize the fat to provide the energy.
I was thinking of buying exogenous ketones for my mother. She plays golf daily but gained some weight as of late. My mother does not want to do the diet but I was thinking this might help her with energy and losing weight. Another person told me it would help her. But then I got to thinking, if she went into Ketosis, then wouldn’t she get the keto flu rather than get energy and mental clarity? Would I need to tell her to take it everyday?
“Adequate dietary carbohydrate is critical to raise muscle glycogen to high levels in preparation for the next day’s endurance competition or hard training session. Accordingly, during the 24 h prior to a hard training session or endurance competition, athletes should consume 7-12 g of carbohydrate per kilogram of body weight. However, during the 24 h prior to a moderate or easy day of training, athletes need to consume only 5-7 g of carbohydrate per kilogram of body weight.”
The bottom line? If you’re thinking about trying the ketogenic diet, run it by your doctor first — regardless of any preexisting health conditions. And consult a registered dietitian nutritionist (find one at EatRight.org) to find a nutrition professional who can work with you to create a meal plan you can stick to. People with kidney disease or a history of disordered eating should avoid the diet, and people with type 1 diabetes may want to avoid it, as well. If you have risk factors for heart disease, you’ll want to speak with your doctor before considering the diet.
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).
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]
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

The keto diet isn’t new, and it’s been around for nearly a century. It was originally developed to treat people with epilepsy. In the 1920s, researchers found that raised levels of ketones in the blood led to fewer epileptic seizures in patients. The keto diet is still used today to treat children with epilepsy who don’t respond well to anti-epileptic drugs.[2]

For example, a key component of safe and lasting fat loss is your capability to tap into your body’s own storage fat for energy. This access to fat cannot happen if your body is constantly drawing on carbohydrate reserves and blood glucose for energy. In the type of moderate- to high-carbohydrate diets you’ve learned are widely recommended by prevailing nutrition science, not only does the utilization of fat for energy become far less crucial (since you’re constantly dumping readily available sugar sources into your body), but your metabolism never becomes efficient at using fat. There is a growing body of evidence proving that a high-fat, low-carbohydrate diet results in faster and more permanent weight loss than a low-fat diet. Furthermore, appetite satiety and dietary satisfaction significantly improve with a high-fat, low-carbohydrate diet that includes moderate protein.
Nutritional ketosis is a natural metabolic state in which your body adapts to burning fat rather than carbohydrates as its primary fuel. It is clinically proven to directly reduce blood sugar (as measured by HbA1c), improve insulin sensitivity (as measured by HOMA-IR) and reduce inflammation (as measured by white blood cell count and CRP). Nutritional ketosis can be induced by following a ketogenic diet. Learn more in our FAQ below!
Alcoholic ketoacidosis (AKA) presents infrequently, but can occur with acute alcohol intoxication, most often following a binge in alcoholics with acute or chronic liver or pancreatic disorders. Alcoholic ketoacidosis occurs more frequently following methanol or ethylene glycol intoxication than following intoxication with uncontaminated ethanol.[11]
The brain is composed of a network of neurons that transmit signals by propagating nerve impulses. The propagation of this impulse from one neuron to another is typically controlled by neurotransmitters, though there are also electrical pathways between some neurons. Neurotransmitters can inhibit impulse firing (primarily done by γ-aminobutyric acid, or GABA) or they can excite the neuron into firing (primarily done by glutamate). A neuron that releases inhibitory neurotransmitters from its terminals is called an inhibitory neuron, while one that releases excitatory neurotransmitters is an excitatory neuron. When the normal balance between inhibition and excitation is significantly disrupted in all or part of the brain, a seizure can occur. The GABA system is an important target for anticonvulsant drugs, since seizures may be discouraged by increasing GABA synthesis, decreasing its breakdown, or enhancing its effect on neurons.[7]
“To achieve the relatively high rates of intake (up to 90 grams/hour) needed to optimize results in events lasting longer than three hours, athletes should practice consuming carbohydrates during training to develop an individual strategy, and should make use of sport foods and drinks containing carbohydrate combinations that will maximize absorption from the gut and minimize gastrointestinal disturbances.”
In addition to the seaweed and glycogen carbohydrates mentioned above, the Inuit can access many plant sources. The stomach contents of caribou contain a large quantity of partially digested lichens and plants, which the Inuit once considered a delicacy. They also harvested reindeer moss and other lichens directly. The extended daylight of the arctic summer led to a profusion of plant life, and they harvested plant parts including berries, roots and stems, as well as mushrooms. They preserved some gathered plant life to eat during winter, often by dipping it in seal fat.[71]
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!!
Other research further supports the potential benefits of this diet. For example, preliminary studies link following the keto diet to reduced symptoms of Alzheimer’s disease. (4) Previous research suggests it may also help reverse metabolic syndrome, manage Parkinson’s disease, has been proven to help control seizures in children with epilepsy, and, according to the results of a small pilot study, may potentially even improve symptoms of polycystic ovary syndrome (PCOS). (5, 6, 7)
“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.
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.
The keto diet is often called a fad diet. Make no mistake: it is. But unlike other trendy diets, the keto diet is unique because it actually pushes the body into an alternate, natural metabolic state called ketosis. When this happens, you can reliably expect a few negative side effects, notably those that come with the "keto flu." But other side effects emerge only when people implement the keto diet poorly, typically by failing to eat balanced, nutrient-rich foods as a part of a high-fat, low-carb diet.
Take coconut oil for example. The coconut oil industry loves to market the idea that relatively inexpensive and abundant coconut oil is a great source of MCTs because it’s “62% MCT oil”, but the problem is that studies show you can’t get many useful ketogenic MCT’s from just eating coconut oil or even most brands of “MCT oil”, which are often is diluted with lauric acid, a cheap, hugely abundant part of coconut oil that is typically marketed as an MCT oil.
Long-term disruption of menstruation can bring on serious side effects, including low bone density. “This is because estrogen is very important to bone health,” says Yawitz. “Studies have also found prolonged menstrual irregularity to increase risk for cardiovascular disease, depression, anxiety, and sexual dysfunction. It’s important to contact your ob-gyn if your cycles become irregular or if you stop having periods.”

In theory, all of this is possible. A study published in the Journal of Nutrition did find an association between having more severe bacterial vaginosis and consuming diets higher in total fat and saturated fat. But the keto diet is still a relatively new rage, and not enough scientific studies have been done to determine whether "keto crotch" is really a risk of the keto diet.

I am not a doctor and this is not to be taken, interpreted or construed as medical advice. Please talk with a licensed medical professional about this. These are just my own personal thoughts and not a prescription or a diagnosis or any form of health care whatsoever. Your mother can avoid the "keto flu" by adding sufficient sodium to her diet and staying well hydrated, especially in the first few days of starting to reduce carbohydrates. The keto flu could also be called “carbohydrate withdrawal symptoms” because of the effects on hormonal and electrolyte balance. If you're not already using a device to measure ketones in your body, I recommend this one: https://bengreenfieldfitness.com/ketonix As far as how much to take, it all depends….you can actually do more than two servings per day if you want, and you can experiment to see how many servings your body should handle. You should know that it would be very difficult to overdose on ketones. They are water soluble, so any excess ketones will be eliminated mainly via the urine. Hope this helps!
If you prefer a more direct, customized approach, 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. Additionally, if I'm "out of your price range" (yes, yes, I know I can be a spendy guy to access) I have a team of coaches I've personally trained who can help you here: https://greenfieldfitnesssystems.com/product-cate…
The keto diet changes the way your body converts food into energy. Eating a lot of fat and very few carbs puts you in ketosis, a metabolic state where your body burns fat instead of carbs for fuel. When your body is unable to get glucose from carbs, your liver converts fatty acids from your diet into ketones, an alternative source of energy. Burning ketones in place of glucose reduces inflammation and spurs weight loss.[1]
Wondering what fits into a keto diet — and what doesn’t? “It’s so important to know what foods you’ll be eating before you start, and how to incorporate more fats into your diet,” says Kristen Mancinelli, RD, author of The Ketogenic Diet: A Scientifically Proven Approach to Fast, Healthy Weight Loss, who is based in New York City. We asked her for some guidelines.
Hi Ben great science & sound advice. May I share with the group? I’m 42, in australia, have been an alcoholic for 10 yrs. In April 2016 I gave up drinking & started living strictly ketogenic. In 3 months I dropped 25 kilos. I have cheated on weekends but I go through a fast of sorts on Mondays to get back into ketosis by Tues. I work afternoon / evenings so I wake at 10.30am take a pre workout drink with raspberry ketones & a splash of mct oil & all my vitamins as well. I then do weights for an hr then get ready to go to work. I take 2 800ml protein shakes consisting of 20 ml mct & 30grm amino enhanced protein. I work in warehousing so I walk anywhere between 10 km & 5 km a nite. I feel great all the time, thanks largely to your research & advice. If have any thoughts or opinions I’d love hear them.
I am not an athlete. I am a mid 30’s male with a sedentary lifestyle. I am 5’10” and 250lbs. I have mild hypertension, high triglycerides, and pre-diabetes. I have eaten whatever I want and as much as I want for years. I have recently started walking/jogging 3-4 times a week, taking fish oil, and eating significantly less carbs plus added fish and steak. Is this diet appropriate and safe for me?
A small Feb. 20, 2017, study looked at the impact of a six-week ketogenic diet on physical fitness and body composition in 42 healthy adults. The study, published in the journal Nutrition & Metabolism, found a mildly negative impact on physical performance in terms of endurance capacity, peak power and faster exhaustion. Overall, researchers concluded, “Our findings lead us to assume that a [ketogenic diet] does not impact physical fitness in a clinically relevant manner that would impair activities of daily living and aerobic training.” The “significant” weight loss of about 4.4 pounds, on average, did not affect muscle mass or function.

“Loss of muscle mass as we age has a number of serious consequences,” notes Clark. “Muscle is metabolically active and helps boost daily energy expenditure and mitigate age-related weight gain.” Losing muscle mass can also decrease functional strength and heighten the risk of falls, notes Clark. Falls are the top cause of death from injury in older populations, according to the Institute of Medicine Division of Health Promotion and Disease Prevention.


The bottom line? If you’re thinking about trying the ketogenic diet, run it by your doctor first — regardless of any preexisting health conditions. And consult a registered dietitian nutritionist (find one at EatRight.org) to find a nutrition professional who can work with you to create a meal plan you can stick to. People with kidney disease or a history of disordered eating should avoid the diet, and people with type 1 diabetes may want to avoid it, as well. If you have risk factors for heart disease, you’ll want to speak with your doctor before considering the diet.
This article is excellent and I’ve actually read it a few times just to make sure I’m absorbing as much as possible. With that said can we talk a bit about protein? Why does it seem like protein is taking a back seat? What about the athlete who needs to maintain and/or increase muscle mass. I don’t want to make any assumptions and with all the research I’ve done along with personal testing into Keto it just seems to me that protein and its benefits are not a discussion point in this diet. Why?
Protein will induce an insulin response in the body, if consumed in high amounts. The most intuitive way to start a keto diet for most people is by removing all of the carbs they have been eating. Typically people will replace those calories by increasing their lean meat consumption. That's a recipe for disaster! Keeping protein moderate is an often overlooked, but very important part of a keto diet. Most people need around 0.6g to 1.0g of protein per pound of lean body mass.

"Many of the richest sources of fiber, like beans, fruit, and whole grains are restricted on the ketogenic diet," registered dietician Edwina Clark told Everyday Health. "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."

The Inuit are often cited as an example of a culture that has lived for hundreds of years on a low-carbohydrate diet.[42] However, in multiple studies the traditional Inuit diet has not been shown to be a ketogenic diet.[43][44][45][46] Not only have multiple researchers been unable to detect any evidence of ketosis resulting from the traditional Inuit diet, but the ratios of fatty-acid to glucose were observed at well below the generally accepted level of ketogenesis.[44][47][45][46] Furthermore, studies investigating the fat yields from fully dressed wild ungulates, and the dietary habits of the cultures who rely on them, suggest that they are too lean to support a ketogenic diet.[48][49] With limited access to fat and carbohydrates, cultures such as the Nunamiut Eskimos—who relied heavily on caribou for subsistence—annually traded for fat and seaweed with coastal-dwelling Taremiut.[48]
In addition, most studies that compare carbohydrate utilization with fat utilization fail to take into account the fact that full “fat adaptation” that allows you to gain all the benefits of using fat as a fuel actually takes time – often more than four weeks – and up to a couple years. But since most studies that compare fat and carbohydrate burning are short-term, you rarely see the benefits of this kind of fat adaptation actually fleshed out in research. Instead, the average research participant begins the study in a non-fat adapted state, gets either a high fat or high carb diet, then launches into exercise. But in an ideal study, that person would have followed either a high-fat or high-carb diet for many months before getting their fat burning capability investigated.
Infants and patients fed via a gastrostomy tube can also be given a ketogenic diet. Parents make up a prescribed powdered formula, such as KetoCal, into a liquid feed.[19] Gastrostomy feeding avoids any issues with palatability, and bottle-fed infants readily accept the ketogenic formula.[31] Some studies have found this liquid feed to be more efficacious and associated with lower total cholesterol than a solid ketogenic diet.[18] KetoCal is a nutritionally complete food containing milk protein and is supplemented with amino acids, fat, carbohydrate, vitamins, minerals and trace elements. It is used to administer the 4:1 ratio classic ketogenic diet in children over one year. The formula is available in both 3:1 and 4:1 ratios, either unflavoured or in an artificially sweetened vanilla flavour and is suitable for tube or oral feeding.[51] Other formula products include KetoVolve[52] and Ketonia.[53] Alternatively, a liquid ketogenic diet may be produced by combining Ross Carbohydrate Free soy formula with Microlipid and Polycose.[53]

Great article! As someone who just started a “ketogenic diet” two weeks ago, I am opting to hold off on using ketone supplements for the following reason. You state how “Keto-adaptation occurs when you have shifted your metabolism to relying on fat-based sources, instead of glucose (sugar) sources, as your primary source of fuel.” If the goal is to “switch” our body’s energy supply to ketones and one uses supplemental ketones, how do they really ever know if their body has successfully accomplished this goal if they are using supplemental ketones? Aren’t they getting a false sense of ketosis if their blood or breath tests show them above 0.5 millimolar through the use of the supplements? I understand that it may take me longer to reach ketosis naturally but I guess I see it was worth it to truly reap all of the benefits that you outline in your article.
The ketone bodies are possibly anticonvulsant; in animal models, acetoacetate and acetone protect against seizures. The ketogenic diet results in adaptive changes to brain energy metabolism that increase the energy reserves; ketone bodies are a more efficient fuel than glucose, and the number of mitochondria is increased. This may help the neurons to remain stable in the face of increased energy demand during a seizure, and may confer a neuroprotective effect.[56]
Thanks for all of the great info!! I have Hashimoto’s and would really like to try a high fat/low carb diet. You mentioned that this might not be a good option for people with thyroid issues. How do you recommend I modify my diet to lose weight taking into consideration the Hashimoto’s. I take Westhroid, a non-synthetic thyroid supplement to help with my sluggish thyroid. Thanks so much for any advice you can give me. :)

I've been on the diet for about a month and a half now and I've noticed that my vaginal odors have gotten MUCH stronger... (It smells like a mix between urine and discharge... I'm not exactly sure how vaginas are 'supposed' to smell like. Many say 'musky' but I feel like that's too mild of a word... It's much stronger than 'musk' for me :/ ). My discharge is white in color and it doesn't smell fishy. Sometimes when it dries on my underwear it's a light yellow? Has this happened to anyone before? Is it because of my change in diet (if so, can anybody explain why?), or could it be something else?
Stock up: Jet.com's new City Grocery service (available in select markets) makes it easy to ensure you always have keto-friendly veggies in the fridge. We love their delivery scheduling tool; simply fill your cart, then decide which day and timeframe you'd like your groceries delivered. One of our faves: Urban Roots Green Squash Veggie Noodles are great for whipping up low-carb "pasta" dishes.
For any long 90+ minute workouts or competitions for which glycogen depletion is a potential issue, use Glycofuse, but use half of the recommended serving of it, and add one scoop of Catalyte electrolytes, one scoop of Aminos, and one serving of medium chain triglycerides in the form of Brain Octane, KetoCaNa or KETO//OS (pick your poison, it’s up to you).
“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.
In addition, most studies that compare carbohydrate utilization with fat utilization fail to take into account the fact that full “fat adaptation” that allows you to gain all the benefits of using fat as a fuel actually takes time – often more than four weeks – and up to a couple years. But since most studies that compare fat and carbohydrate burning are short-term, you rarely see the benefits of this kind of fat adaptation actually fleshed out in research. Instead, the average research participant begins the study in a non-fat adapted state, gets either a high fat or high carb diet, then launches into exercise. But in an ideal study, that person would have followed either a high-fat or high-carb diet for many months before getting their fat burning capability investigated.
I'm at 240 now and actually weigh less than I did in high school. Have a decent amount of excess skin that skews my actual weight. Thankfully the government of Canada pays for plastic surgery in my case because it could lead to health problems in the future. Surgery is in about 8 or so months and I'm quite excited to start a completely new chapter of my life once it's done.
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