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.
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.
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).
First, I want to thank you for all of your dedication and work in providing this site. The difficulty of maintaining a healthy weight is a big problem for so many people. My personal question & issue in staying on Keto is my craving for fresh fruit. This a.m I had a large fresh peach along with my “Bullet Proof” coffee. Have I now sabotaged today’s Keto eating?
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 
Decades later, when low carb became the best thing since sliced bread, people were calling it the Air Force Diet and the Drinking Man’s; Atkins and Paleo; Comet and Cupid. Then, in 2016, podcaster and MMA commentator Joe Rogan discussed keto once on his show and his loyal following of fitness enthusiasts and life optimizers took it and ran (especially in the mornings, to increase fat burning during the fasting state). 
The addition of MCT powder to ketones serves the purpose of maintaining endogenous production of ketone bodies by stimulating fatty acid oxidation in the liver, which then causes the production of even more ketone bodies. In this transcript from a podcast with Dr. Dom D’Agostino it is mentioned that MCT’s cross the blood-brain barrier straight to the brain. So not only are the ketones being used by the brain as an alternative fuel but so are MCT’s.
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.
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.
I am trying to get back into keto. I did it before and I was so happy when I lost 10lbs (I did the keto for a month). I am ready to go back to this lifestyle. All this information is very helpful, I have written it all down so it can be easier for me to remember what is allowed and what is not. Looking forward to get back on this keto journey. Thank you for all the great info.

Ketones are a special type of fat that can stimulate the pathways that enhance the growth of new neural networks in the brain. A ketogenic diet is one that is high in fats, and this diet has been a tool of researchers for years, used notably in a 2005 study on Parkinson’s patients finding an improvement in symptoms after just 28 days. The improvements were on par with those made possible via medication and brain surgery. Other research has shown the ketogenic diet to be remarkably effective in treating some forms of epilepsy, and even brain tumors.


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.
“Suddenly and drastically reducing carbohydrates sets your body up for a double whammy of sorts,” says Yawitz. “The brain’s favorite fuel is glucose, which is most easily created from carbohydrates. In very-low-carb diets, the brain has to adjust to using ketones from digested fats for energy. To add to this discomfort, your kidneys release more electrolytes as insulin levels fall.” Additionally, your total body water decreases as carbohydrates become depleted on a keto diet, notes Clark. The result? What’s known as the keto flu, which could cause constipation, nausea, headache, fatigue, irritability, cramps, and other symptoms. Don’t fret, though: Many of these symptoms are short term and should last only a few days to weeks. Make sure to drink plenty of water to help your body cope with these symptoms. And call your doctor if symptoms — especially nausea — are prolonged, advises Yawitz.

In its 2016 report “Healthy Eating Guidelines & Weight Loss Advice,” the Public Health Collaboration, a U.K. nonprofit, evaluated evidence on low-carbohydrate, high-fat diets. (The Keto diet falls under the LCHF umbrella.) Among 53 randomized clinical trials comparing LCHF diets to calorie-counting, low-fat diets, a majority of studies showed greater weight loss for the Keto-type diets, along with more beneficial health outcomes. The collaboration recommends weight-loss guidelines that include a low-carbohydrate, high-fat diet of real (rather than processed) foods as an acceptable, effective and safe approach.
Fuels and feeds your brain: Ketones provide an immediate hit of energy for your brain, and up to 70% of your brain’s energy needs when you limit carbs.[6] Fat also feeds your brain and keeps it strong. Your brain is at least 60% fat, so it needs loads of good fats to keep it running.[7] Essential fatty acids such as omega-3s help grow and develop the brain, while saturated fat keeps myelin — the layer of insulation around the brain — strong so your neurons can communicate with each other.
“For events longer than 60 minutes, consuming 0.7 g carbohydrates·kg-1 body weight·h-1 (approximately 30-60 g·h-1) has been shown unequivocally to extend endurance performance. Consuming carbohydrates during exercise is even more important in situations when athletes have not carbohydrate-loaded, not consumed pre-exercise meals, or restricted energy intake for weight loss. Carbohydrate intake should begin shortly after the onset of activity; [and continue] at 15- to 20-min intervals throughout the activity.”
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]
My keto journey began with chicken and avocado, like many high-fat brethren before me, until I eventually found the paleo cookbooks and created a little diet-friendly life for myself, devoid of family party-friendly foods but productive and communal in its own way. I was joining the online forums. I was reading studies about the health benefits of keto. I was drinking the bone-broth Kool-Aid, believing my fasting states and butter coffee were catapulting me towards some sort of psychophysiological excellence. I lost around 15lbs in 2015 because I didn’t allow myself most of the foods I usually “overdid” and was motivated not only by the progress but by the exclusive, cultish energy of ketosis. We were not the Google diet generation -- we were Google scholar. We treated epilepsy, after all, and our fearless keto leaders preached the Good News to all who would listen, then verbally abused well-meaning bloggers and medical professionals who suggested that extreme dieting might be unhealthy and unsustainable. Amen?
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.

Implementing the diet can present difficulties for caregivers and the patient due to the time commitment involved in measuring and planning meals. Since any unplanned eating can potentially break the nutritional balance required, some people find the discipline needed to maintain the diet challenging and unpleasant. Some people terminate the diet or switch to a less demanding diet, like the modified Atkins diet or the low-glycaemic index treatment diet, because they find the difficulties too great.[42]
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.)
Decades later, when low carb became the best thing since sliced bread, people were calling it the Air Force Diet and the Drinking Man’s; Atkins and Paleo; Comet and Cupid. Then, in 2016, podcaster and MMA commentator Joe Rogan discussed keto once on his show and his loyal following of fitness enthusiasts and life optimizers took it and ran (especially in the mornings, to increase fat burning during the fasting state). 
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.
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. :)
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?
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?
The same goes for people with type 2 diabetes. While some preliminary research suggests the keto diet may be safe and effective for certain people with type 2 diabetes, there’s still the risk for low blood sugar, especially for those on insulin, and the keto diet omits certain food groups known to benefit those with this disease. For example, a study published in September 2016 in the journal Nutrients highlights the importance of whole grains for helping to control weight as well as episodes of high blood sugar. Whole grains are off-limits on the ketogenic diet.

Have you heard all the buzz about the keto diet and want to know more? Did a friend tell you they’re “in ketosis” and you got interested? Here’s everything you need to know about ketogenic diets and being in ketosis for fat loss, brain function, satiety, and performance. Editor’s Note: This article is being updated … Continue reading The Keto Diet: Next Big Thing or Dangerous Fad?
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.
Keto-adaption is a complex set of metabolic processes in which the body shifts from using primarily glucose for energy to using largely ketones and fat for energy. Achieving ketosis doesn’t mean the body is maximizing the use of these ketones; it takes longer than a few days for the body to get used to burning fat and ketones as its predominant fuels.
Hi Stacey, I can’t give medical advice and definitely recommend following your doctor’s recommendations. You can ask him/her if low carb would be better suited for you. Also, you may want to double check with him/her if the kidney concern was related to high protein, because that is a common misconception about keto – it is not a high protein diet/lifestyle.

Keep in mind that if your crotch begins to have a very unusual smell, whether or not you are on the keto diet, you may want to see your doctor. Don't just tell everyone on Reddit about how much your crotch smells. Regardless of your gender, an unusual smell could be a sign of an infection or some other condition that needs proper medical attention. Even if you don't have a medical problem, your doctor can tell you what kinds of smells are normal and not normal. In other words, he or she could lower your concerns about what's going on in the lower part of your body.
Shifting your metabolism and achieving ketosis may speed up weight loss and result in other health benefits, like more energy and a lower blood pressure. But while ketosis is a preferred nutritional state for some people, it isn’t recommended for everyone — and it’s not a good long-term eating approach due to its restrictive nature, which may lead to potentially dangerous nutritional deficiencies.
I am new to Keto, but not new to a low carb diet. I just started a keto diet 8 days ago. My goals for being on the diet is a little body recomp (nothing major, a few pounds of fat loss), and moving to fat as primary fuel for endurance with a focus on trail ultra marathon races and training. Along with Keto I am doing heart rate training using MAF and OFM as a guide. supplemented with body weight and free weight strength training and some HITT.
If you want to make some enemies very quickly, just jump on to social media and say "the keto diet stinks." Because there are certainly a number of people who swear by the keto diet. Some of them will even swear at you if you say anything bad about the diet. Supporters of the diet claim that the keto diet will help lose weight relatively quickly, clear your mind, make you feel better, and even clear up your acne, because you no longer are taking in carbohydrates that "cause inflammation." People who question the diet have raised concerns about whether maintaining such a high fat diet is effective and healthy in long run. After all, high fat diets could raise the risk of various chronic medical conditions such as heart disease and cancer.

Now, there a few things you should know before you begin using KETO//OS. First, ketones naturally act as a diuretic, so you lose salt, potassium, calcium and magnesium, and it is generally encouraged to increase sodium intake with ketones. That’s why there is extra sodium added to KETO//OS. The combination of BHB with sodium also acts as a bit of a buffer to buffer natural ketone acidity.


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 asked a few former keto dieters what their experience was like. My friend Anthony said he lost a ton of weight because he was no longer allowed to have basically anything unhealthy he had previously enjoyed, which ties back to “low rule complexity.” But he eventually stopped losing weight, started craving the foods he’d removed, and was nervous he’d gain weight again without these restrictions. A former professor of mine found herself in a state of general malaise that never passed (more on that later), and felt much more energetic overall when she dropped the diet.
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.
My keto journey began with chicken and avocado, like many high-fat brethren before me, until I eventually found the paleo cookbooks and created a little diet-friendly life for myself, devoid of family party-friendly foods but productive and communal in its own way. I was joining the online forums. I was reading studies about the health benefits of keto. I was drinking the bone-broth Kool-Aid, believing my fasting states and butter coffee were catapulting me towards some sort of psychophysiological excellence. I lost around 15lbs in 2015 because I didn’t allow myself most of the foods I usually “overdid” and was motivated not only by the progress but by the exclusive, cultish energy of ketosis. We were not the Google diet generation -- we were Google scholar. We treated epilepsy, after all, and our fearless keto leaders preached the Good News to all who would listen, then verbally abused well-meaning bloggers and medical professionals who suggested that extreme dieting might be unhealthy and unsustainable. Amen?
For the keto gurus who serve as keto's staunchest evangelicals, conversations swirl around oft-repeated talking points, and any sense of negativity is quickly batted away. I spoked to several "gurus.” The claims they made are already on most low-carb blogs: It’s gonna suck at first, but it’s Worth It. Fat makes you full. Blood sugar will go down. Insulin will be on point. You’ll realize that which has sat dormant in your body for too long -- a demigod. Devoid of carbs, your body will reconstruct in such a way that Zeus descended from parted clouds to congratulate you on your blood test results.
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.

During my private and group therapy sessions I learned a lot of information that would be beneficial to the average dieter. My first therapy assignment was to go out and buy a food I used to enjoy, so I purchased M&Ms and relearned how to allow myself a little bit each day. I learned that binges are triggered not by enjoyment of a food but by the feeling that you should stop eating and can’t. I was taught about intuitive eating, which helped me break down my regimented eating schedule and lean into my natural inclination to seek variety of foods in order to reduce cravings. You can find all of these materials online.


2) I'm currently using Ketocana and in that section you state "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 fat or eat copious amounts of fats, but want to simultaneously maintain high levels of blood ketones." – How would eating copious amounts of fat be a negative? Wouldn't that help contribute to a ketogenic state?

Great post!! I’m a 41 year old Master CrossFit athlete, been in keto / LCHF Primal lifestyle for the past 9 years. I feel that my performance has improved a lot and continues to improve pretty significantly. I was a top 200 Master Open Qualifier on 2016 and 2017 and I’m usually on the podium of local competitions so my performance is really not bad…and I’m totally fat adapted. I follow sort of a TKD where I sometimes eat carbs at night during the week, but never above 100g so It doesn’t even kick me out of ketosis due to activity level. I’ve been playing with some measurements and I noticed that my BG reading after high intensity training sessions is really high (up to 180mg/dl). But it goes down fast (sometimes it goes down to 50mg/dl but I show no side effect of hypo, function completely normal). From my research, the high glucose post high intensity is normal and due to the stressful response of the exercise and also because my liver is producing the glucose from gluconeogeneses to provide it for the workouts, when needed. This only happens when the workouts are long, above 30 minutes.

“Given that there is no known detriment to consumption of a high-carbohydrate diet (other than body weight gain due to water retention) and some research reports a benefit, it is recommended that all athletes consume a high-carbohydrate training diet, i.e., at least 60-70% of energy as carbohydrate (7-10 g/kg), and increase this to 65-85% for the few days before competition. Use of a carbohydrate supplement before and during exercise will likely improve performance of intermittent, high-intensity sprints.”
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.
Look into cold showers and ice baths for relief from depression along with all the other benefits it provides. If you’re willing to push your comfort zone, you’ll find that cold showers/baths provide a monumental difference. There’s some research out there that identifies the benefits of combining specific ketogenic diets and ice baths. And I used this to increase gains in the gym, reduce inflammation, feel better in general, builds patience and raises tolerance levels. It’s impressive stuff. Cold and heat thermogenesis for the win (heat would be sauna/steam room, but cold is what helps you sleep better and will help you with depression). Good luck mate!
Articles and information on this website may only be copied, reprinted, or redistributed with written permission (but please ask, we like to give written permission!) The purpose of this Blog is to encourage the free exchange of ideas. The entire contents of this website is based upon the opinions of Dave Asprey, unless otherwise noted. Individual articles are based upon the opinions of the respective authors, who may retain copyright as marked. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the personal research and experience of Dave Asprey and the community. We will attempt to keep all objectionable messages off this site; however, it is impossible to review all messages immediately. All messages expressed on The Bulletproof Forum or the Blog, including comments posted to Blog entries, represent the views of the author exclusively and we are not responsible for the content of any message.
But sadly, whether due to government subsidy of high carb foods like corn and grain, funding from big companies like Gatorade and Powerbar, our sugar-addicted Western palates, or the constant (unfounded) fear mongering about saturated fats and heart disease, the type of research that shows these fat-burning and performance benefits of carbohydrate restriction simply get shoved under the rug.
Net carbs are what we track when following a ketogenic diet. This calculation is pretty straightforward. Net Carbs = Total Carbs – Fiber. For example, one cup of broccoli has 6g of total carbs and 2.4g of fiber. That would mean one cup of broccoli has 3.6g of net carbs. We count Net Carbs  because dietary fiber does not have a significant metabolic effect. 
×