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. 

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]


Checking your ketone level is one way to know if you’re in ketosis. This metabolic state usually kicks in after three or four days of restricting your carbohydrate intake or going through periods of intermittent fasting. You don’t have to visit a doctor to measure your level. Pick up a ketone urine test from a nearby drug store, or use a blood sugar meter that’s capable of measuring ketones.
BHB is the primary ketone your body can most efficiently use as fuel during exercise and at rest (especially when you’re keto-adapted), it is the most stable of the ketones, and it is actually found in nature in many foods including eggs and milk. A “BHB salt” is simply a compound that consists of sodium (Na+), potassium (K+), and the ketone body beta-hydroxybutyrate.
A: The amount of weight you lose is entirely dependent on you. Obviously adding exercise to your regimen will speed up your weight loss. Cutting out things that are common “stall” causes is also a good thing. Artificial sweeteners, dairy, wheat products and by-products (wheat gluten, wheat flours, and anything with an identifiable wheat product in it).

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.
They mimic ketosis, to answer your question in short. Best to get fat adapted and use ketones to get the best of both worlds and to enhance fat burning abilities. They will allow you to use glucose and fatty acids simultaneously, yes. 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.
Before I highly suggest that you don’t purge your bread products, I’m going to play devil’s cautious-and-hardly-audible advocate and say, yes, drastically cutting carb and sugar intake can have health benefits: it can increase levels of good cholesterol, reduce blood sugar, and all that stuff. But you can accomplish these same goals by, for example, replacing Wonder bread with a healthier carb. There's no need to side-eye the croutons your server forgot to omit like they’re a physical manifestation of the Seven Deadly Sins.
As a matter of fact, it’s more dangerous to have high levels of cholesterol and high levels of CRP than low levels of cholesterol and high levels of CRP – even if your high levels of cholesterol are “healthy”, big fluffy LDL particles, and not small, dense vLDL particles. In other words, no matter how many healthy fats you’re eating, these fats may actually come back to bite you if you’re creating high inflammation from too much exercise, not enough sleep, exposure to toxins and pollutants, or a high-stress lifestyle.
This article really bothers me in that if you do a few incorrect things with this diet, it will actually do more harm than a full carb diet. I have been in ketosis for a month or so but to what detriment? Based on the “ketosis darkside” list you highlighted, i could be doing any or all of these without realising. Could i share with you my meal plans and see if in your opinion they are beneficial and healthy or if im digging myself an early grave?
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.
During the 1920s and 1930s, when the only anticonvulsant drugs were the sedative bromides (discovered 1857) and phenobarbital (1912), the ketogenic diet was widely used and studied. This changed in 1938 when H. Houston Merritt, Jr. and Tracy Putnam discovered phenytoin (Dilantin), and the focus of research shifted to discovering new drugs. With the introduction of sodium valproate in the 1970s, drugs were available to neurologists that were effective across a broad range of epileptic syndromes and seizure types. The use of the ketogenic diet, by this time restricted to difficult cases such as Lennox–Gastaut syndrome, declined further.[10]
In ketogenesis, two acetyl-CoA molecules instead condense to form acetoacetyl-CoA via thiolase. Acetoacetyl-CoA momentarily combines with another acetyl-CoA via HMG-CoA synthase to form hydroxy-β-methylglutaryl-CoA. Hydroxy-β-methylglutaryl-CoA form the ketone body acetoacetate via HMG-CoA lyase. Acetoacetate can then reversibly convert to another ketone body—D-β-hydroxybutyrate—via D-β-hydroxybutyrate dehydrogenase. Alternatively, acetoacetate can spontaneously degrade to a third ketone body (acetone) and carbon dioxide, although the process generates much greater concentrations of acetoacetate and D-β-hydroxybutyrate. When blood glucose levels are low, ketone bodies can be exported from the liver to supply crucial energy to the brain.[28]
-Cardiovascular Disease: High blood sugar has been shown to increase the risk for cardiovascular events, cardiovascular disease, and cardiovascular mortality—while lower glucose levels result in lower cardiovascular risk. Coronary artery disease risk has been shown to be twice as high in patients with impaired glucose tolerance, compared with patients with more normal glucose tolerance. The risk for stroke increases as fasting glucose levels rise above 83 mg/dL. In fact, every 18 mg/dL increase beyond 83 results in a 27 percent greater risk of dying from stroke. Incidentally, glucose can “stick” to cholesterol particles and render these particles extremely dangerous from a heart health standpoint, which is why it’s all the more important to control blood sugar levels if you’re eating a “high-fat diet.”
Another appropriate fruit on the keto diet, ½ cup of cubed raw cantaloupe has only 5.8 g of net carbohydrates. The same serving size is also low in calories, with 27 g, as well as in sugar, with 6.3 g. Plus,it offers vitamins and nutrients such as 214 mg of potassium (4.6 percent DV), 29.4 mg of vitamin C ( 49 percent DV), and 2,706 IU of vitamin A ( 54.1 percent DV). Cantaloupes are delicious and refreshing, and eating the fruit may help you stay full longer.

In Asia, the normal diet includes rice and noodles as the main energy source, making their elimination difficult. Therefore, the MCT-oil form of the diet, which allows more carbohydrate, has proved useful. In India, religious beliefs commonly affect the diet: some patients are vegetarians, will not eat root vegetables or avoid beef. The Indian ketogenic diet is started without a fast due to cultural opposition towards fasting in children. The low-fat, high-carbohydrate nature of the normal Indian and Asian diet means that their ketogenic diets typically have a lower ketogenic ratio (1:1) than in America and Europe. However, they appear to be just as effective.[54]


Other causes of diarrhea on the keto diet include consuming a diet low in fiber (fiber helps ward off diarrhea by bulking up stool) and eating processed low-carb foods like shakes and bars that may contain sugar alcohols. These sugar alcohols can ferment in the gut and cause gastrointestinal discomfort. Yawitz suggests limiting foods labeled “sugar free” if you’re prone to gas or diarrhea when you eat them. And you may want to gradually adjust your carbs downward and your fats upward. “Also build your diet around [naturally] high-fiber, low-carb foods like avocado and nonstarchy vegetables such as broccoli, cauliflower, and asparagus,” she says. Other keto-friendly ways to get more fiber include chia seeds, almonds, and coconut.
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.
Radical diets like keto bring radical change, and I’m not referring to pounds you might shed from depriving your body of an essential macronutrient; I’m talking about changes in your social world, your relationship with food, and your mental health. I’m talking about the diet industry convincing us that if we pass on eating out with friends to do our at-home cardio fat-busting workout before roasting another variation on a chicken dinner, we’re going to feel joyous and at peace with ourselves once we reach our fitness “goals.” And we’re actually going to keep the weight off.
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.
C12 is about 50+% of coconut oil, and it requires a pit stop in the liver rather than getting immediately converted into energy like the other MCT’s listed above. This is why it is more accurately described as an LCT, not an MCT like marketers claim. It raises cholesterol more than any other fatty acid. It is also commonly cited as having antimicrobial benefits, which is does – except the shorter chain MCT oils are more effective against candida yeast infections, and even gonorrhea and chlamydia.

Wow! Amazing article. I don’t read blogs regularly, but I’ll be reading more of yours. I am on day 11 of a fast to get me into ketosis; 7 days bone broth and now on day-4 water only. Intentions are weight loss (10# down, 15# more to go) and immunity improvement/gut help. Planning 9 days of whey water, fermented veggies and mad probiotics when the water days are done (day 14?). After this fast I want to stay fat adapted, start training again and get down to 8% body fat. I believe you have cut that journey significantly with this article. Thank you.
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.
I have never been able to fix the electrolyte loss symptoms I get on the ketogenic diet (heart palpitations, dry mouth, air hunger) by supplementing with electrolytes. Blogosphere says that is just the transition, but mine seem to only get worse over time. I’ve tried about 2 grams of extra potassium, 800 mg extra magnesium, and 3 grams extra salt (in addition to my already liberally salted foods) spread throughout the day. This did not help. Also does eating salt alone cause you to retain water and therefore retain the rest of the electrolytes without supplementing them?
The bottom line? If you’re thinking about trying the ketogenic diet, run it by your doctor first — regardless of any preexisting health conditions. And consult a registered dietitian nutritionist (find one at EatRight.org) to find a nutrition professional who can work with you to create a meal plan you can stick to. People with kidney disease or a history of disordered eating should avoid the diet, and people with type 1 diabetes may want to avoid it, as well. If you have risk factors for heart disease, you’ll want to speak with your doctor before considering the diet.
I've tried that before(enzymedica digest gold for example) but it didn't seem to help much. It seems from testing that I have some heavy metal stuff going on and there might have been a chronic mold exposure in the past that is still reeking havoc and I imagine that might be affecting this pretty heavily. I will definitely be sticking to the avocadoes and coconut and 100% dark chocolate because I can't tolerate dairy. The hard part is figuring out what is the bare minimum of starch to make my gut feel good and be regular and at the same time become fat adapted and get those increased cognition and longevity benefits!!
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]
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.

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]
Adherence to a keto diet food list isn’t always great, though. A review published in January 2015 in the Journal of Clinical Neurology found that only 45 percent of participants were able to follow the approach as prescribed. “The poor compliance was attributed to side effects, social isolation, and cravings,” says Yawitz. And some people in the study “reported the diet simply wasn’t helping them lose weight,” she adds. Brissette agrees with this line of thinking. “In my opinion, the keto diet isn't sustainable and takes the joy and fun out of eating,” she says.
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. 

But while carbohydrates can help you have a better workout, go faster, or go longer, this only applies to acute, in-the-moment performance. Once you take a look (which you’re about to do) at the long-term effects of chronic high blood sugar levels, things change drastically. If the damage that you’re above to discover is worth it to you, then you are either mildly masochistic or you value performance much more than health.
In other words, I personally found that while following “strict ketosis”, things became eerily similar to the days in college when I was a competitive bodybuilder pursuing sub-3% body fat percentages. I simply wasn’t the most fun guy to hang out with in social situations due to my extreme dietary restrictions, the intense self-control became nearly exhausting, and when I traveled, I missed out on many culinary experiences, such as homemade ravioli in Rome, freshly baked crostinis in the Basque regions of Spain, and Korean rice bowls in Seoul.
Keep up electrolytes. The major electrolytes in our bodies are sodium, potassium and magnesium. Because a low carb diet (especially a keto diet!) reduces the amount of water you store, this can flush out electrolytes and make you feel sick (called “keto flu”). This is temporary, but you can avoid or eliminate it by salting your food liberally, drinking broth (especially bone broth), and eating pickled vegetables. Some people also choose to take supplements for electrolytes, but it’s best to first consult a doctor that understands and supports keto/low carb lifestyles.

Elevated blood ketone levels is the sign of ketosis, while certain subjective symptoms can also signal ketosis. Increased mental clarity, less brain fog, and diminished appetite are fairly common among people in ketosis. The ketogenic diet specifically has its own assortment of symptoms. Fortunately, the negative symptoms such as constipation, diarrhea, and bad breath are often temporary and tend fade as your body becomes better at fat burning and naturally producing ketones. The positive symptoms of ketosis coincide with higher levels of ketones in the blood. This may occur after several weeks of adhering to the ketogenic diet or very shortly after ingesting exogenous ketones.
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.
Would be curious to receive feedback on any of the above! And if anyone is interested in more info on my future Ketone product which will taste great, have 11.7g of BHB, 30 servings and priced lower than all the competitors, then message me on FB under Rhys Kabra, or email [email protected] for status updates on the upcoming new Brand of Ketone products! :)
Some people group tomatoes with vegetables, but a tomato is actually a fruit. Low in fat but also carbs (with just 2.4 g of net carbs per ½ cup), tomatoes are also keto-friendly. The same serving size of tomatoes contains 2.4 g of sugar and 16 calories. Among their health benefits, tomatoes contain lycopene, which research suggests may help prevent heart disease.
If you’re serious about maximizing the benefits of ketosis, then forego coconut oil, MCT liquid oil, olive oil, etc. and instead use Brain Octane as your oil of choice for recipes like bulletproof coffee, or in teas, salad dressings, or as a sushi or entrée flavor enhancer. For a slightly less expensive, but not quite as effective form of MCT, use XCT oil.

During the 1920s and 1930s, when the only anticonvulsant drugs were the sedative bromides (discovered 1857) and phenobarbital (1912), the ketogenic diet was widely used and studied. This changed in 1938 when H. Houston Merritt, Jr. and Tracy Putnam discovered phenytoin (Dilantin), and the focus of research shifted to discovering new drugs. With the introduction of sodium valproate in the 1970s, drugs were available to neurologists that were effective across a broad range of epileptic syndromes and seizure types. The use of the ketogenic diet, by this time restricted to difficult cases such as Lennox–Gastaut syndrome, declined further.[10]


Awesome info. I’ve been LCHF moderate protein (about 1 g per lean lbs/mass) and 50-100g of carbs for about a year. I’d consume around 2500 cals. I’m active 4-5 days a week (60-90 min cycling sessions) I started using MCT/Butter coffee. It surpressd my appetite and I would only eat whole food at lunch/dinner…still LCHF, but since my appetite was lower I was only takin in about 1800 cals. After about 2 weeks I started to gain body fat. Do you think the reduced caloric intake is the culprit? Should I “force” myself to eat…maybe up the MCT intake to make up the difference?
And what I’m writing has nothing to do with taking supplements to induce ketosis or whatever. I believe these things are covered in Volek & Phoney’s book The Art and Science of Low Carb Living, which I would have thought you to be very familiar with. The iodine stuff you can read about in Iodine, Why We Need, Why We Can’t Live Without It by Brownstein.
-Pancreatic Dysfunction: The beta cells in the pancreas that produce the insulin to help control blood sugar become dysfunctional with high blood glucose, raising the risk for type 2 diabetes. Researchers have discovered that beta cell issues are detectable in people whose glucose levels spike two hours after eating, despite those levels staying within the range considered normal and safe by the medical establishment.
Keto-adaptation, AKA “becoming a fat burning machine”, occurs when you have shifted your metabolism to relying on fat-based sources, instead of glucose (sugar) sources, as your primary source of fuel. Your body increases fat oxidation, and breaks down fats into ketones to be used as the primary energy source. Depending on your current level of carbohydrate intake (takes longer if you’re pretty sugar addicted), this process can take two weeks to six months to fully train your body to, but once done, it’s done, and you have achieved fat-burning status that can stick with you for life.
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?
I talk about that quite a bit here :https://bengreenfieldfitness.com/2015/09/things-your-pee-can-tell-you-about-your-body/
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.
Those new to keto should be testing to see if their bodies are in ketosis, regardless of method. Testing, in general, is the most objective way to know if you’re in ketosis. There can be some subjective benefits of ketosis: appetite suppression, fat loss, low blood sugar, improvement in mental cognition and focus. But before recognizing these subjective benefits, it’s important to track and measure the level of ketones in the blood to ensure ketosis on a physical level.
After about two to seven days of following the keto diet, you go into something called ketosis, or the state your body enters when it doesn't have enough carbs for your cells to use for energy. That's when you start making ketones, or organic compounds that your bod then uses in place of those missing carbs. At this point, your body also starts burning fat for more energy, says Beth Warren, R.D., founder of Beth Warren Nutrition and author of Living A Real Life With Real Food.

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.
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.

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.


In many developing countries, the ketogenic diet is expensive because dairy fats and meat are more expensive than grain, fruit and vegetables. The modified Atkins diet has been proposed as a lower-cost alternative for those countries; the slightly more expensive food bill can be offset by a reduction in pharmaceutical costs if the diet is successful. The modified Atkins diet is less complex to explain and prepare and requires less support from a dietitian.[55]
One proposed benefit of the ketogenic diet is that you may lose more weight compared with other diets. One study of 17 obese men found that a high-protein, low-carb ketogenic diet over a four-week period helped reduce hunger, resulting in lower food intake and more weight loss compared with a high-protein, medium-carbohydrate nonketogenic diet. (3)

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!
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