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.
Exogenous ketosis comes from an external source. Consuming exogenous ketones, like a ketone drink containing a ketone ester or a ketone salt, raises blood ketone levels. The body isn't producing ketones in this state, but still remains in ketosis from having ketones introduced from an outside source. However, the body isn't ketogenic–that specifically means the body is producing its own ketones.
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.
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!
^ Fumagalli M, Moltke I, Grarup N, Racimo F, Bjerregaard P, Jørgensen ME, Korneliussen TS, Gerbault P, Skotte L, Linneberg A, Christensen C, Brandslund I, Jørgensen T, Huerta-Sánchez E, Schmidt EB, Pedersen O, Hansen T, Albrechtsen A, Nielsen R (September 2015). "Greenlandic Inuit show genetic signatures of diet and climate adaptation". Science. 349 (6254): 1343–7. Bibcode:2015Sci...349.1343F. doi:10.1126/science.aab2319. hdl:10044/1/43212. PMID 26383953.
Why is the keto diet good for you? A keto diet is one that prioritizes fats and proteins over carbohydrates. It can help reduce body weight, acne, and the risk of cancer. Find out about the mechanisms through which it achieves these benefits and the research that supports it. This MNT Knowledge Center article also discusses the risks of the diet. Read now
The day before admission to hospital, the proportion of carbohydrate in the diet may be decreased and the patient begins fasting after his or her evening meal.[19] On admission, only calorie- and caffeine-free fluids[37] are allowed until dinner, which consists of "eggnog"[Note 8] restricted to one-third of the typical calories for a meal. The following breakfast and lunch are similar, and on the second day, the "eggnog" dinner is increased to two-thirds of a typical meal's caloric content. By the third day, dinner contains the full calorie quota and is a standard ketogenic meal (not "eggnog"). After a ketogenic breakfast on the fourth day, the patient is discharged. Where possible, the patient's current medicines are changed to carbohydrate-free formulations.[19]
It seems like everyone is talking about the keto diet — the high-fat, low-carb eating plan that promises to turn your body into a fat-burning machine. For that reason, keto has surged in popularity over the past year as a lose-weight-fast strategy. Thank Hollywood A-listers and professional athletes like Halle Berry, Adriana Lima, and Tim Tebow who’ve publicly touted the diet’s benefits, from shedding weight to slowing down aging. Here’s everything you need to know about going keto.

If I see a TSH above 2.0 or a trend towards higher values in someone who is testing repeatedly, I get worried – and prefer to see TSH at 0.5-2.0. Of course, this doesn’t mean that you begin to shove carbohydrates indiscriminately down the hatch. However, it means that your high-fat, low-carb diet should include thyroid supporting foods rich in iodine and selenium, such as sea vegetables and brazil nuts, and should also include carbohydrates timed properly, such as before, during or after workouts, when the carbohydrate is more likely to be utilized for energy and less likely to spike blood glucose levels.

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.


While it is believed that carbohydrate intake after exercise is the most effective way of replacing depleted glycogen stores,[72][73] studies have shown that, after a period of 2–4 weeks of adaptation, physical endurance (as opposed to physical intensity) is unaffected by ketosis, as long as the diet contains high amounts of fat, relative to carbohydrates.[74] Some clinicians refer to this period of keto-adaptation as the "Schwatka imperative" after Frederick Schwatka, the explorer who first identified the transition period from glucose-adaptation to keto-adaptation.[75]


I started a ketogenic diet about 5 weeks ago and have experimented with KetoCaNa and KetoForce along with Now Foods MCT oil (which is made of caprylic and capric acid) in the hopes of easing the transition into ketosis. I don’t use it every day, but often before an aerobic based workout. I was wondering if taking these exogenous ketones at the beginning of a ketogenic diet helps you become keto adapted by up regulating the body’s handling of ketones. And conversely, does taking exogenous ketones down regulate or affect lypolysis since BHB is readily available? My main priority at this point is fat loss.
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.
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.
Intermittent fasting is another way to achieve ketosis. This doesn’t suggest going days without food, but rather intermittent fasting. You can eat for eight hours and then fast for 16 hours, or eat a low-calorie diet for a few days (about 1,200 daily calories if you’re a woman and 1,500 daily calories if you’re a man). As you take in less food, your body uses more of its fat stores for fuel.
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.
Although many hypotheses have been put forward to explain how the ketogenic diet works, it remains a mystery. Disproven hypotheses include systemic acidosis (high levels of acid in the blood), electrolyte changes and hypoglycaemia (low blood glucose).[19] Although many biochemical changes are known to occur in the brain of a patient on the ketogenic diet, it is not known which of these has an anticonvulsant effect. The lack of understanding in this area is similar to the situation with many anticonvulsant drugs.[56]
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!
When you eat less than 50 grams of carbs a day, your body eventually runs out of fuel (blood sugar) it can use quickly. This typically takes 3 to 4 days. Then you’ll start to break down protein and fat for energy, which can make you lose weight. This is called ketosis. It's important to note that the ketogenic diet is a short term diet that's focussed on weight loss rather than the pursuit of health benefits. 
This answer made me sad. Having lived in New York all of my life, I from a young age saw loved ones fall victim to spontaneous gluten intolerance and restaurants run to their rescue with accommodating menus.  This is why I get annoyed. What’s a dietary prescription for someone who wants to go to a dinner party and be able to eat a meal that was prepared for them? Keto is cultish not for its members’ radical commitment to a dietary restriction but for their lack of full participation in the outside world.

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?


When you eat less than 50 grams of carbs a day, your body eventually runs out of fuel (blood sugar) it can use quickly. This typically takes 3 to 4 days. Then you’ll start to break down protein and fat for energy, which can make you lose weight. This is called ketosis. It's important to note that the ketogenic diet is a short term diet that's focussed on weight loss rather than the pursuit of health benefits. 
First, a little background: Eric Westman, MD, director of the Duke Lifestyle Medical Clinic, explained to Health in a previous interview that in order to successfully follow the keto diet, you need to eat moderate amounts of protein, reduce your carb intake, and increase fats. When you reduce your carb consumption, your body turns to stored fat as its new fuel source—a process called ketosis. To stay in ketosis, followers of the keto diet must limit their carbs to 50 grams a day, Dr. Westman says.
Following the ketogenic diet and achieving ketosis may be beneficial if you’re living with type 2 diabetes and need to manage your symptoms. Limiting carbohydrate intake is crucial with type 2 diabetes because too many carbs can increase blood glucose levels, which can damage blood vessels and lead to vision problems, kidney problems, and nerve problems.
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!!
It seems like everyone is talking about the keto diet — the high-fat, low-carb eating plan that promises to turn your body into a fat-burning machine. For that reason, keto has surged in popularity over the past year as a lose-weight-fast strategy. Thank Hollywood A-listers and professional athletes like Halle Berry, Adriana Lima, and Tim Tebow who’ve publicly touted the diet’s benefits, from shedding weight to slowing down aging. Here’s everything you need to know about going keto.
In dairy cattle, ketosis is a common ailment that usually occurs during the first weeks after giving birth to a calf. Ketosis is in these cases sometimes referred to as acetonemia. A study from 2011 revealed that whether ketosis is developed or not depends on the lipids a cow uses to create butterfat. Animals prone to ketosis mobilize fatty acids from adipose tissue, while robust animals create fatty acids from blood phosphatidylcholine (lecithin). Healthy animals can be recognized by high levels of milk glycerophosphocholine and low levels of milk phosphocholine.[76] Point of care diagnostic tests are available and are reasonably useful.[77]
MCT oil is extracted primarily from coconut oil, and derives unique benefits from its shorter fatty acid chain length. Most dietary fat contains 12 carbons in the fatty acid chain, while MCTs are only 6 - 12 carbon chains in length. Shorter chain length allows for easier absorption and rapid conversion to energy in the liver, specifically caprylic (C8) and capric (C10).
Ben – curious about your thoughts on this. I went into ketosis (using LOTS of coconut oil) but it raised my cholesterol and doc was worried about my lp(a) level (17mg/dL on VAP) even though crp was 0.5, trigs 51 and a1c was 5.2. Advised a low fat diet. Have you seen this before with folks on a lchf/ketosis diet and is there anything to be concerned about? Off to read your coconut oil article. Thank you!
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]
KETO//OS contains a specifically engineered ratio of ketone mineral salts blended with a high fiber based medium chain triglyceride (MCT) formulation, so you get a potent delivery of both exogenous ketones and medium chain triglycerides.  It is simply a powder that you mix with 8-10 oz of water. Within 15-30 minutes it puts your body into a full and deep state of ketosis.
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.
Apparently, Dominic’s research seems to be suggesting the fact that diet-induced ketosis from a high-fat, low-carb intake, especially when combined with the use of nutrition supplements such as powdered ketones or MCT oil, can vastly reduce the need for the brain to use oxygen to burn glucose. This is because the brain can use up to around 75% of its fuel from ketones. So a ketone-fed or a fat-adapted brain can be better equipped to withstand low oxygen availability and potentially support longer breath-hold times. Dominic’s research also shows that in the presence of ketosis, the brain and body are able to resist the potential cell damage of long periods of time with low oxygen, also known as “hypoperfusion”.
Thank you for this article as it cleared up a bunch of stuff for me. I started trying to get into ketosis back in August and lost 20lbs in about 6 weeks. Then it all stopped but had another 20lbs I wanted to loose. I had a hard time staying in ketosis and gave up about a week ago with the holidays approaching. Anyways I glazed over all the technical and science facts as it makes my head spin and might of missed it but my only question is what is the food portion of the diet like? The drinks are the easy part, do you have a diet plan that is good for someone that hits the gym hard 4-5 days a week for and hour and half. 45 min weights and 30-45 min cardio? It’s what I struggle with most the food and what attracted me to a ketogenic diet in the first place is eating 1 or 2 meals a day and being satisfied.
Some people on a keto or low carb diet choose to count total carbs instead of net carbs. This makes it more difficult to fit in more leafy greens and low carb vegetables (which are filled with fiber), so you should only try that if you don’t get results with a net carb method. And, start with reducing sugar alcohols and low carb treats before deciding to do a “total carbs” method.
The concentration of ketone bodies may vary depending on diet, exercise, degree of metabolic adaptation and genetic factors. Ketosis can be induced when a ketogenic diet is followed for more than 3 days.[34] This induced ketosis is sometimes called nutritional ketosis.[35] This table shows the concentrations typically seen under different conditions[1]
There are theoretically no restrictions on where the ketogenic diet might be used, and it can cost less than modern anticonvulsants. However, fasting and dietary changes are affected by religious and cultural issues. A culture where food is often prepared by grandparents or hired help means more people must be educated about the diet. When families dine together, sharing the same meal, it can be difficult to separate the child's meal. In many countries, food labelling is not mandatory so calculating the proportions of fat, protein and carbohydrate is difficult. In some countries, it may be hard to find sugar-free forms of medicines and supplements, to purchase an accurate electronic scale, or to afford MCT oils.[54]
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]
I knew keto was on the The Today Show when relatives began dropping the term in the same charming way your grandmother might refer to “the Instagram.” They knew it was low carb and that it worked, because that’s what the show told them. But they couldn’t explain the state of “ketosis” or why their Yummy Yummy Dark Chocolate Sea Salt Breakfast Replacement Keto Bar was a better choice for weight loss than, like, cutting back on alcohol.
Ben – curious about your thoughts on this. I went into ketosis (using LOTS of coconut oil) but it raised my cholesterol and doc was worried about my lp(a) level (17mg/dL on VAP) even though crp was 0.5, trigs 51 and a1c was 5.2. Advised a low fat diet. Have you seen this before with folks on a lchf/ketosis diet and is there anything to be concerned about? Off to read your coconut oil article. Thank you!
Ketosis is a metabolic state where most of the body's energy supply comes from ketone bodies in the blood, in contrast to a state of glycolysis where blood glucose provides most of the energy. Ketosis is characterized by serum blood concentrations of ketone bodies over 0.5 millimolar with low and stable levels of insulin and blood glucose. However, with ketone supplementation (as you’ll learn about later in this article) ketosis can actually be induced even when there are high levels of blood glucose.
So in the end, I ordered 1kg of pure BHB Magnesium from a supplier in China and I will be developing my own Ketone product with 30 servings as a lower price than all the competitors, and with more Magnesium, and Calcium in it than Sodium so that it tastes the best and actually helps with weight loss (which Magnesium is proven to do at the right amount). What the companies don’t tell you is that actually Sodium BHB is the cheapest, then Calcium BHB and then Magnesium BHB to source so I would be interested in knowing if what you wrote is actually true or just an excuse to make the product cheaper. Probably a mix of both.
“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.
My question is: what if I want to be in ketosis for all the reasons mentioned in the Life Extension article and because I don't feel a strong urge to eat in between meals when I go lower carb and if I up carb intake I get hungrier more frequently and get urges . . . BUT on the flip side, I don't seem to digest fat all that well(dairy in particular is a no-no) and constipation is an issue and starchy carbs seem to help with that. It's a bit of a catch-22.
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