^ Greenberg CR, Dilling LA, Thompson GR, Seargeant LE, Haworth JC, Phillips S, Chan A, Vallance HD, Waters PJ, Sinclair G, Lillquist Y, Wanders RJ, Olpin SE (April 2009). "The paradox of the carnitine palmitoyltransferase type Ia P479L variant in Canadian Aboriginal populations". Molecular Genetics and Metabolism. 96 (4): 201–7. doi:10.1016/j.ymgme.2008.12.018. PMID 19217814.


“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.”
Long-term use of the ketogenic diet in children increases the risk of slowed or stunted growth, bone fractures, and kidney stones.[18] The diet reduces levels of insulin-like growth factor 1, which is important for childhood growth. Like many anticonvulsant drugs, the ketogenic diet has an adverse effect on bone health. Many factors may be involved such as acidosis and suppressed growth hormone.[38] About one in 20 children on the ketogenic diet develop kidney stones (compared with one in several thousand for the general population). A class of anticonvulsants known as carbonic anhydrase inhibitors (topiramate, zonisamide) are known to increase the risk of kidney stones, but the combination of these anticonvulsants and the ketogenic diet does not appear to elevate the risk above that of the diet alone.[39] The stones are treatable and do not justify discontinuation of the diet.[39] Johns Hopkins Hospital now gives oral potassium citrate supplements to all ketogenic diet patients, resulting in one-seventh of the incidence of kidney stones.[40] However, this empiric usage has not been tested in a prospective controlled trial.[9] Kidney stone formation (nephrolithiasis) is associated with the diet for four reasons:[39]
One more thing that I noticed is that my HR does not move Beyond a certain point. I can still perform quite at a high level and faster than most people at my box but weirdly enough it’s like there’s a block on my HR which doesn’t allow it to move beyond 160 bpm. I’m not sure if this is good or bad! Could I go even faster if my HR would pass this limit?? It is a physiological barrier created by the glycogen sparing mechanism that doesn’t allow my body to move after a certain point so it won’t have to tap into my glycogen stores or force my body to go into gluconeogenesis?? If I added some more carbs around my workouts would it be easier to get the glycolytic pathway to work more effectively since it’d be faster and easier fuel? I read about the downregulation of PDH enzymes after prolonged keto and I constantly worry that I dont use my glycolytic pathway as effective anymore. I LOVE this lifestyle but at the same time, as athletes; we’re always thinking on how to improve performance. What are your thoughts?! Thank you so much!!
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!
These affect your brain and spine, as well as the nerves that link them together. Epilepsy is one, but others may be helped by a ketogenic diet as well, including Alzheimer’s disease, Parkinson’s disease, and sleep disorders. Scientists aren’t sure why, but it may be that the ketones your body makes when it breaks down fat for energy help protect your brain cells from damage.
After initiation, the child regularly visits the hospital outpatient clinic where they are seen by the dietitian and neurologist, and various tests and examinations are performed. These are held every three months for the first year and then every six months thereafter. Infants under one year old are seen more frequently, with the initial visit held after just two to four weeks.[9] A period of minor adjustments is necessary to ensure consistent ketosis is maintained and to better adapt the meal plans to the patient. This fine-tuning is typically done over the telephone with the hospital dietitian[19] and includes changing the number of calories, altering the ketogenic ratio, or adding some MCT or coconut oils to a classic diet.[18] Urinary ketone levels are checked daily to detect whether ketosis has been achieved and to confirm that the patient is following the diet, though the level of ketones does not correlate with an anticonvulsant effect.[19] This is performed using ketone test strips containing nitroprusside, which change colour from buff-pink to maroon in the presence of acetoacetate (one of the three ketone bodies).[45]
Watermelon is a staple summer fruit and another low-carb way to help satisfy your sweet tooth on keto. Each ½ cup of diced watermelon has 5.4 g of net carbs. It’s also an acceptable choice when dieting because of its high water content. The ½ cup serving size of watermelon has about 23 calories and 4.7 g of sugar. This juicy fruit also offers 432 IU of vitamin A, which is 8.6 percent of the DV.

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.”


Along with biomarker testing, subjective symptoms can provide an indication of your ketosis. Sometimes, early side effects of the diet result from carbohydrate withdrawal. This can be known as the "keto flu;" symptoms include nausea, fatigue, headache and dry mouth. They're short-term, typically lasting about a week or less. Keep in mind, however, that we are all different. Our bodies react in different ways. Some of us may experience these symptoms later than sooner, to a lesser extent, or not at all.
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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]
But wait, there’s one loophole. Have polycystic ovary syndrome (PCOS)? Then the keto diet may help regulate your periods. “Women with PCOS have high insulin levels, which cause sex hormone imbalances,” notes Yawitz. In a small study published in the journal Nutrition & Metabolism, subjects with PCOS following a ketogenic diet for six months noted improvements in their menstrual cycles — and a small number of women became pregnant, overcoming previous infertility obstacles. “This study was very small, so we can’t make recommendations for all women with PCOS based on its findings,” says Yawitz. “And really, any diet that leads to weight loss should help in PCOS.”
So if your high-fat diet includes a high amount of roasted seeds or roasted nuts, nut butters, heated oils such as heated coconut oil or heated extra virgin olive oil, barbecued meats or meats cooked at very high temperatures, then your triglyceride count is going to go up. You should have triglycerides that are less than 150mg/dL, and a triglyceride to HDL ratio that is no more than 4:1, and in most of the healthiest people I’ve worked with, triglycerides are under 100 and the triglyceride to HDL ratio is less than 2:1. If your ratio is whacked, your ketotic diet isn’t doing you any favors.
On the ketogenic diet, carbohydrates are restricted and so cannot provide for all the metabolic needs of the body. Instead, fatty acids are used as the major source of fuel. These are used through fatty-acid oxidation in the cell's mitochondria (the energy-producing parts of the cell). Humans can convert some amino acids into glucose by a process called gluconeogenesis, but cannot do this by using fatty acids.[57] Since amino acids are needed to make proteins, which are essential for growth and repair of body tissues, these cannot be used only to produce glucose. This could pose a problem for the brain, since it is normally fuelled solely by glucose, and most fatty acids do not cross the blood–brain barrier. However, the liver can use long-chain fatty acids to synthesise the three ketone bodies β-hydroxybutyrate, acetoacetate and acetone. These ketone bodies enter the brain and partially substitute for blood glucose as a source of energy.[56]

This is the second shortest form of MCT, also rare and comprising about 8% of coconut oil. It is slower to turn into energy but less expensive than C8. XCT Oil is triple-distilled in a non-oxygen atmosphere with no solvents, and it contains C10 and C8, because these are the only two MCT oils that turn into ATP quickly without the liver. You would need 6 tablespoons of coconut oil to get one tablespoon of XCT oil.
"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."
People use a ketogenic diet most often to lose weight, but it can help manage certain medical conditions, like epilepsy, too. It also may help people with heart disease, certain brain diseases, and even acne, but there needs to be more research in those areas. Talk with your doctor first to find out if it’s safe for you to try a ketogenic diet, especially if you have type 1 diabetes.

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
A ketogenic diet helps control blood sugar levels. It is excellent for managing type 2 diabetes, sometimes even leading to complete reversal of the disease. This has been proven in studies. It makes perfect sense since keto lowers blood-sugar levels, reduces the need of medications and reduces the potentially negative impact of high insulin levels.
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?
What about fruits and vegetables? All fruits are rich in carbs, but you can have certain fruits (usually berries) in small portions. Vegetables (also rich in carbs) are restricted to leafy greens (such as kale, Swiss chard, spinach), cauliflower, broccoli, Brussels sprouts, asparagus, bell peppers, onions, garlic, mushrooms, cucumber, celery, and summer squashes. A cup of chopped broccoli has about six carbs.
If you have a functioning pancreas that can produce insulin – i.e. you don’t have type 1 diabetes – it would be extremely hard or, most likely, impossible to get ketoacidosis even if you tried. That’s because high ketone levels result in release of insulin, that shuts down further ketone production. In other words, the body has a safety net that normally makes it impossible for healthy people to get ketoacidosis.
Hi I’m new to Keto. I have been reading about it, and understanding what to eat and what not to eat. My problem is I’m not sure if I’m doing it correctly. I’m constantly hungry whereas information reads that I will never be hungry. I use fats as required along with topping up with vegetables in my meals yet this does not fill me up. I haven’t experienced the Keto flu and I’ve even put on weight! I have been doing this for about 3 weeks now. Any ideas where I am going wrong.
Adipose tissue can be used to store fatty acids for regulating temperature and energy.[21] These fatty acids can be released by adipokine signaling of high glucagon and epinephrine levels, which inversely corresponds to low insulin levels. High glucagon and low insulin correspond to times of fasting or to times when blood glucose levels are low.[23] Fatty acids must be metabolized in mitochondria in order to produce energy, but free fatty acids cannot penetrate biological membranes due to their negative electrical charge. So coenzyme A is bound to the fatty acid to produce acyl-CoA, which is able to enter the mitochondria.
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.

^ Hochachka PW, Storey KB (February 1975). "Metabolic consequences of diving in animals and man". Science. 187 (4177): 613–21. Bibcode:1975Sci...187..613H. doi:10.1126/science.163485. PMID 163485. In the terminal stages of prolonged diving, however, even these organs must tolerate anoxia for surprisingly long times, and they typically store unusually large amounts of glycogen for this purpose.

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?

I tried a lot of shit to get thin. I used to eat exactly seven almonds to stave off hunger before bed. I finished my last meal at 4pm and my breakfast at noon. I passed on croutons. I worshipped fitness influencers so much that my ex photoshopped a photo of Tim Ferriss and I cooking together. I swore by kettlebelling. I peed on test strips at the drug test clinic I worked at to measure my ketone levels. I put MCT oil and butter in my coffee and avoided bread for nearly three years. I thought about making an Instagram of myself dumbbell lunging on a weight bench with the reps in the description. To some people, I was #goals.
Food is your body’s primary source of energy, and three main nutrients in foods supply your body with this energy. These are carbohydrates, fat, and protein. Typically after eating a meal, your body will first break down carbohydrates from foods, and then fat and protein.Ketosis is a natural metabolic state that occurs when your body doesn’t have enoughcarbs (or glucose) for energy, so it burns fat instead.
So if your high-fat diet includes a high amount of roasted seeds or roasted nuts, nut butters, heated oils such as heated coconut oil or heated extra virgin olive oil, barbecued meats or meats cooked at very high temperatures, then your triglyceride count is going to go up. You should have triglycerides that are less than 150mg/dL, and a triglyceride to HDL ratio that is no more than 4:1, and in most of the healthiest people I’ve worked with, triglycerides are under 100 and the triglyceride to HDL ratio is less than 2:1. If your ratio is whacked, your ketotic diet isn’t doing you any favors.
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.

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.
Hi Ben…first, I have learned so much from you, thank you! I’m interested in using exogenous ketone supplements and I have a question for you. I just read the transcript of an interview Dave Asprey did with Dr. Richard Veech (episode 299). He advises against them, and says they can even be harmful. I was disappointed to read this, and wanted to ask you about it, since I respect your opinion greatly….thank you.
"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.
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