Before long, keto was everywhere. Grocery stores were filling their aisles with bars. Restaurants were touting keto-friendly options. "Keto" has joined "Dinners," "Healthy," "Slow-Cooker," and "Cookbook" among the tabs on beloved food site Delish. Other food sites -- this one included -- dog-piled on the SEO potential, going in on hot keto content. The chain reaction was swift and all-encompassing. And as it went viral, keto began appealing to vulnerable minds everywhere. My mind included. 
So which MCT to pick? Brain Octane (pure C8) provides the fastest rise in ketones and burns the cleanest, with minimal gut irritation. XCT oil is more affordable but works more slowly with less direct cognitive effects. The capric acid C10 in XCT Oil doesn’t break down into ketones as quickly as pure caprylic C8, but capric acid C10 is more affordable, so you can save money by going with the XCT oil. XCT oil still goes to brain energy, just not as quickly as Brain Octane. Both can be used for energy without processing by the liver, unlike many other fats and oils.
I'd recommend starting with glucose and hemoglobin A1C, along with a good multi like https://bengreenfieldfitness.com/multi and a fish oil like the one at greenfieldfitnesssystems.com – Anyways, I'd be happy to help you via a personal one-on-one consult. Just go to https://bengreenfieldfitness.com/coaching. and then choose a 20 or 60 minute consult, whichever you'd prefer. I can schedule ASAP after you get that.
Next, you need to ease yourself into this stuff. As I mentioned earlier, KETO//OS is blended with MCT’s, which can cause digestive distress if you’re not used to consuming them. This is due to the fact that your body has not yet adapted to the increased fats in your diet, and is less efficient at utilizing ketones as its fuel source. Once your body has adapted to MCT in the diet, the digestive distress will resolve.  But I recommend you start slowly with just about a half a serving a day, and over two weeks, build up to a full serving twice a day.
Amazing article – gonna have to print it and read it again. To much to break down in one sitting. Thanks Ben – you’ve pulled together so much insight and references that’s given me greater confidence and conviction. I’m 50 and use to be super active and a seasoned athlete but after a few ‘mid life surgical interventions’ I had to find a better way… Ketogenics has been that for me… no more inflammation… I can’t tell you how great it’s been to be pain free! Keep leading from the front.

The reason purity matters is that C17 is a byproduct of most MCT oil production processes, and it, along with C6, is a major cause of throat burning and gut irritation. Most MCT’s on the market are manufactured via chemical and solvent based refining, which involves using chemicals like hexane and different enzymes and combustion chemicals, such as sodium methoxide. But ideally, you should get an MCT oil that is made using triple steam distillation in a non-oxygen atmosphere to avoid lipid oxidation and create a purer end-product.


The ketogenic diet doesn’t put a cap on saturated fat or even trans fats. The latter are fats you should always avoid. Read ingredient labels and avoid any food with partially hydrogenated oils, aka trans fats. These fats heighten your LDL (“bad”) cholesterol levels and lower your HDL (“good”) cholesterol levels. They also raise your risk of heart disease and stroke, according to the American Heart Association.
I think there is a lot more to the story than ketosis or very low carb for everyone. In my own experience, high carb works much better. I tried very low carb for a long without really feeling amazing, I then switched back to high carb and quickly lost weight and leaned out. I still eat high carb and my strength is better and I'm even leaner now. I find it very difficult to overeat (I obviously eat very 'clean diet').

Typically, to gain lean body mass one needs to have some degree of caloric surplus, or at the very least, not be in a significant deficit. This is especially true when looking to add muscle mass. It is certainly possible to gain muscle mass on a ketogenic diet. For most individuals this would require consuming adequate protein (while still remaining in ketosis), enough calories to support growth, sufficient electrolytes to support muscle function, as well as incorporating progressive resistance training. The type and volume of resistance exercise needed to add lean body mass will be very dependent on the individual and their age, training status, health status, etc. Therefore, the answer to this question can become quite nuanced, but in simple terms, yes, it is very possible to gain lean body mass on a ketogenic diet while still taking advantage of the health promoting effects this way of eating provides.
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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.
There are numerous benefits that come with being on keto: from weight loss and increased energy levels to therapeutic medical applications. Most anyone can safely benefit from eating a low-carb, high-fat diet. Below, you’ll find a short list of the benefits you can receive from a ketogenic diet. For a more comprehensive list, you can also read our in-depth article here >
Kidney stones are a well-noted potential side effect of the ketogenic diet. Research published in the Journal of Child Neurology observed that among children following the keto diet as a treatment for epilepsy, 13 out of 195 subjects developed kidney stones. Children supplementing with potassium citrate in the study noticed a decreased likelihood of kidney stones. Speak with your healthcare practitioner about supplementing if kidney stones are a concern.

If you have high triglycerides and low HDL, or you have any type of genetic issue that would cause you to have high sensitivity to saturated fats then the diet may not actually be for you. I think you should start by reading this: https://bengreenfieldfitness.com/article/nutritio… 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.
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]

About 20% of children on the ketogenic diet achieve freedom from seizures, and many are able to reduce the use of anticonvulsant drugs or eliminate them altogether.[18] Commonly, at around two years on the diet, or after six months of being seizure-free, the diet may be gradually discontinued over two or three months. This is done by lowering the ketogenic ratio until urinary ketosis is no longer detected, and then lifting all calorie restrictions.[46] This timing and method of discontinuation mimics that of anticonvulsant drug therapy in children, where the child has become seizure-free. When the diet is required to treat certain metabolic diseases, the duration will be longer. The total diet duration is up to the treating ketogenic diet team and parents; durations up to 12 years have been studied and found beneficial.[9]
“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.”
I’m missing one key-step in this whole process … I understand (vaguely) how to get into ketosis via diet, starvation, or supplementation. But, my confusion really is with the supplementation method (such as XCT Oil, for example). If I supplement with these to get into ketosis quicker, but haven’t significantly altered to a high-fat diet, won’t I just shift back into glucose-use as soon as I burn out the supplemented ketones?? like within minutes / hours?
Carbohydrates are necessary for the conversion of inactive thyroid hormone to active thyroid hormone, and if you’re on an extremely strict low carbohydrate diet, then you may actually be limiting this conversion. Your TSH is what tells your thyroid gland to “release more hormone,” so your TSH rises when your thyroid gland is underactive, or conversion of inactive to active thyroid hormone is inadequate. A high TSH means that the pituitary gland is releasing its hormone to try to get the thyroid to respond and produce more thyroid hormone. Because of inadequate carbohydrates, TSH will often elevate in a high-fat, low-carber – indicating potential for long-term thyroid and metabolic damage.
2) I have a hard time eating real food soon after rides/workouts. I had used Hammer Recoverite (1scoop instead of suggest serving of 2 and add 1scoop whey isolate protein) in the past because I feel a significant difference the day after with less muscle fatigue. Then I read a previous posts on your opinion of post-workout supplementation ( https://bengreenfieldfitness.com/2013/07/what-to-… ) and I realized the primary ingredient in Recoverite is maltodextrin. Since the 2013 article, has anything changed in your research that you might suggest I add PWO to aid in the muscle fatigue/recovery? (In other words, Is there anything more healthy I can take to replace the Recoverite or should the aminos/electrolytes/carbs/MCT’s from the recipe in this article be sufficient?) Thanks in advance, I appreciate all of your work!
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
^ Jump up to: a b c Clemente FJ, Cardona A, Inchley CE, Peter BM, Jacobs G, Pagani L, Lawson DJ, Antão T, Vicente M, Mitt M, DeGiorgio M, Faltyskova Z, Xue Y, Ayub Q, Szpak M, Mägi R, Eriksson A, Manica A, Raghavan M, Rasmussen M, Rasmussen S, Willerslev E, Vidal-Puig A, Tyler-Smith C, Villems R, Nielsen R, Metspalu M, Malyarchuk B, Derenko M, Kivisild T (October 2014). "A Selective Sweep on a Deleterious Mutation in CPT1A in Arctic Populations". American Journal of Human Genetics. 95 (5): 584–589. doi:10.1016/j.ajhg.2014.09.016. PMC 4225582. PMID 25449608.

"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.
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?
The question then is whether your crotch is like your mouth. Not in general, but in the specific case of ketones. That is, when you are on the keto diet, can ketones also accumulate in your crotch area and then subsequently lead to a new smell? Moreover, if you are woman, could ketones be changing the acidity of your vagina, which then may produce an environment more favorable to certain types of microorganisms? Indeed, the smell of your vagina can depend on the composition of microorganisms there. Some odors, like a strong fishy one, can be the result of an overgrowth of certain microorganisms like bacteria, which is the case in bacterial vaginosis.
Keto is short for ketogenic. If you didn’t already know, it’s a high-fat, low-carb diet. The goal of the ketogenic diet is to get your body into a “ketogenic state,” or a physiological state in which your body is not burning carbohydrates -- which break down to glucose -- but an alternative energy source called ketones, which are produced by the liver when your body is depleted of glucose. Ketones are formed from fat stores. In order for your body to start producing ketones, it needs to first run out of glycogen stores. After you deprive your body of carbs, it takes a bit of time for the glucose to clear out.
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!
Probably, and there are a few reasons why the keto diet usually equals weight-loss gold, says Keatley. For starters, people usually reduce their daily caloric intake to about 1,500 calories a day because healthy fats and lean proteins make you feel fuller sooner—and for a longer period of time. And then there’s the fact that it takes more energy to process and burn fat and protein than carbs, so you're burning slightly more calories than you did before. Over time, this can lead to weight loss.
An interview with University of Florida researcher and scientist Dominic D’ Agostino. In that episode, “A Deep Dive Into Ketosis: How Navy Seals, Extreme Athletes & Busy Executives Can Enhance Physical and Mental Performance With The Secret Weapon of Ketone Fuel“, Dominic highlights his research into the use of ketones to enhance breathhold time and reduce the brain’s requirements for oxygen.
For example, in trained people and athletes who eat a low-carbohydrate, high-fat diet (not to be confused with a low-carbohydrate, high-protein diet), a large amount of fat burning can take place at intensities well above 80 percent maximum oxygen utilization (VO2 max) – allowing for very-high-intensity or long efforts with low calorie intake and also allowing for use of fat fuel stores during long steady-state exercise, even at a relatively fast pace (so much for the “fat burning zone” giving you the best bang for your buck). With high-fat, low-carb intake, you can go hard and still burn tons of fat. In addition, this means that more carbohydrate stores will be available when you really need them, such as for an all-out, 100%, maximum effort.

Under these circumstances, as soon as the body’s limited reserves of glucose starts to run out, your entire body switches its fuel supply to run almost completely on fat. The levels of the fat-storing hormone insulin levels become very low, and fat burning increases dramatically. You thus get easy access your fat stores, and can burn them off. This is great for losing excess weight. Studies prove that keto diets result in more weight loss, faster. There are also more potential benefits.
The diet is extremely regimented and very difficult to stick to, as just one baked potato and one slice of bread could hold an entire day’s worth of carbohydrates. While this is a deterrent for many, Christy Brissette, RD, a private-practice dietitian in Chicago, notes that many of her patients like the diet because of its strictness. “Some of my clients feel that the keto diet works for them because it doesn't involve any calorie counting and the rules are simple to understand,” she says. “They feel they have strict parameters that can take the guesswork out of dieting.”
The question then is whether your crotch is like your mouth. Not in general, but in the specific case of ketones. That is, when you are on the keto diet, can ketones also accumulate in your crotch area and then subsequently lead to a new smell? Moreover, if you are woman, could ketones be changing the acidity of your vagina, which then may produce an environment more favorable to certain types of microorganisms? Indeed, the smell of your vagina can depend on the composition of microorganisms there. Some odors, like a strong fishy one, can be the result of an overgrowth of certain microorganisms like bacteria, which is the case in bacterial vaginosis.
You need to do a “common man’s” version of a good ketogenic nutrition program or discussion. Great article, and I leaned a few things. Those Ketone Salts and other supplements can get pricey. I eat a very low carb and high fat diet and meander in and out of ketosis during the week. A pure ketogenic diet is so restrictive that meals it can get very repetitive during the week. I’d like to learn more about cooking with oils and how temperature effects their qualities. I can only handle eating so much raw food, and I love to cook my greens and other vegetables in bacon fat and coconut oil. It will be next May before I can get my blood work performed (insurance reasons) so until then I’ll need to be careful and hold back on those after supper dark chocolate excursions! Thanks!!
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?
The reason purity matters is that C17 is a byproduct of most MCT oil production processes, and it, along with C6, is a major cause of throat burning and gut irritation. Most MCT’s on the market are manufactured via chemical and solvent based refining, which involves using chemicals like hexane and different enzymes and combustion chemicals, such as sodium methoxide. But ideally, you should get an MCT oil that is made using triple steam distillation in a non-oxygen atmosphere to avoid lipid oxidation and create a purer end-product.
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.)
“Certainly, the quality of fat counts,” says Yawitz. “There’s a big difference nutritionally between bacon and almonds. As much as possible, people set on the keto diet should emphasize plant-based, unsaturated fats like nuts, seeds, olive oil, and avocado, which have even been shown to protect the heart.” If you have high cholesterol or other risk factors for heart disease, you should speak with your doctor before beginning the keto diet. This is because the diet may — but doesn't have to — include large amounts of saturated fat. Some studies have shown increases in cholesterol and triglycerides in people following the diet, while other research reveals that the keto diet may actually decrease heart disease risk as well as saturated fat intake.
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