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!


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

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.
Urine test for diabetes: What you need to know Urine tests for diabetes check for protein, ketones, and glucose. They are frequently used for diagnosing and monitoring diabetes, and to assess people who are experiencing symptoms, such as fatigue or nausea. Depending on the results, recommendations may be given about medication or lifestyle changes that could help. Read now
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?
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.
You state that many athletes and very active people could benefit from 100-200g of carbs a day, and be back in ketosis in a few hours. Any particulars on which kind of activities or say how long/many training sessions would benefit from this to balance hormones. I train mma 3-4 days a week and also do lots of hiit and strength training as well. Just trying to see if this is a situation where i would benefit from your suggestions. Thanks!
Hi Gigi, Low carb and keto is about the balance of macronutrients eaten (fat, protein and carbs), not specifically meat or lack thereof. Most people on keto do eat meat, though some people do vegetarian keto. Fat is actually necessary for many body processes. There is no issue for the kidneys with a high fat diet, but if you eat too much protein that isn’t great for the kidneys. It’s a common misconception that keto is high protein (it isn’t). Keto is great for diabetics as it naturally helps stabilize insulin. All of this being said, please know I’m not a doctor and you should consult your doctor on any medical questions or before starting any diet. If you have more questions that aren’t medical questions, I recommend our low carb & keto support group here.
Short-term results for the LGIT indicate that at one month approximately half of the patients experience a greater than 50% reduction in seizure frequency, with overall figures approaching that of the ketogenic diet. The data (coming from one centre's experience with 76 children up to the year 2009) also indicate fewer side effects than the ketogenic diet and that it is better tolerated, with more palatable meals.[18][50]
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.
I am trying to get back into keto. I did it before and I was so happy when I lost 10lbs (I did the keto for a month). I am ready to go back to this lifestyle. All this information is very helpful, I have written it all down so it can be easier for me to remember what is allowed and what is not. Looking forward to get back on this keto journey. Thank you for all the great info.

Meat products make up a big part of the keto diet, but experts stress the importance of choosing quality. "Since the keto diet is based a lot on animal proteins, it's important to buy organic poultry and grass-fed, organic beef," says Aimee Aristotelous, RD. "Not only do organic selections help with limiting environmental toxins, but grass-fed options of red meats even change the composition of fats." The result, she explains, is that your body is able to better absorb those healthy fats.

"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."


Ben, great article! I recently did my own ketosis experiment and didn’t catch the 100-200g advise until later than I should have, I’m guessing. Great results for 1-2 months but after 3 months I quit sleeping through the night and would wake after about 4 hours of rest each night. My guess is that the extra carbs at night coupled with iodine supplements should allow me to “have my cake and eat it too?” Any other suggestions on the sleep issue? I’ve gone back to High Fat/Low Carb, have improved sleep but I do miss nutritional ketosis and want to try again once my sleep is stable. Thank YOU!!!
Because some fruits have more carbs than others, knowing which to avoid is key for accelerating weight loss and reaping other possible benefits of keto. Just know that large, long-term, randomized controlled trials on the keto diet are limited, so it’s unclear whether keto is safe and effective to follow for the long haul, according to Harvard Medical School.

The ketogenic diet has been studied in at least 14 rodent animal models of seizures. It is protective in many of these models and has a different protection profile than any known anticonvulsant. Conversely, fenofibrate, not used clinically as an antiepileptic, exhibits experimental anticonvulsant properties in adult rats comparable to the ketogenic diet.[58] This, together with studies showing its efficacy in patients who have failed to achieve seizure control on half a dozen drugs, suggests a unique mechanism of action.[56]
Here are a few of the most common side effects that I come across when people first start keto. Frequently the issues relate to dehydration or lack of micronutrients (vitamins) in the body. Make sure that you’re drinking enough water (close to a gallon a day) and eating foods with good sources of micronutrients. To read more on micronutrients, click here >

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.”


Anticonvulsants suppress epileptic seizures, but they neither cure nor prevent the development of seizure susceptibility. The development of epilepsy (epileptogenesis) is a process that is poorly understood. A few anticonvulsants (valproate, levetiracetam and benzodiazepines) have shown antiepileptogenic properties in animal models of epileptogenesis. However, no anticonvulsant has ever achieved this in a clinical trial in humans. The ketogenic diet has been found to have antiepileptogenic properties in rats.[56]
It is possible to combine the results of several small studies to produce evidence that is stronger than that available from each study alone—a statistical method known as meta-analysis. One of four such analyses, conducted in 2006, looked at 19 studies on a total of 1,084 patients.[23] It concluded that a third achieved an excellent reduction in seizure frequency and half the patients achieved a good reduction.[18]
Normal dietary fat contains mostly long-chain triglycerides (LCTs). Medium-chain triglycerides (MCTs) are more ketogenic than LCTs because they generate more ketones per unit of energy when metabolised. Their use allows for a diet with a lower proportion of fat and a greater proportion of protein and carbohydrate,[18] leading to more food choices and larger portion sizes.[4] The original MCT diet developed by Peter Huttenlocher in the 1970s derived 60% of its calories from MCT oil.[15] Consuming that quantity of MCT oil caused abdominal cramps, diarrhea, and vomiting in some children. A figure of 45% is regarded as a balance between achieving good ketosis and minimising gastrointestinal complaints. The classical and modified MCT ketogenic diets are equally effective and differences in tolerability are not statistically significant.[9] The MCT diet is less popular in the United States; MCT oil is more expensive than other dietary fats and is not covered by insurance companies.[18]
I’ll warn you: when you first start using BHB salts like KetoCaNa, it can cause some temporary GI upset until you get acclimated to use. For me, this manifested in just a little bit of gas and bloating that subsided after about one week of use. Additionally, you should know that this product contains salt, so it counts as part of your daily salt intake.
Your glycogen stores can still be refilled while on a ketogenic diet. A keto diet is an excellent way to build muscle, but protein intake is crucial here. It’s suggested that if you are looking to gain mass, you should be taking in about 1.0 – 1.2g protein per lean pound of body mass. Putting muscle on may be slower on a ketogenic diet, but that’s because your total body fat is not increasing as much.5Note that in the beginning of a ketogenic diet, both endurance athletes and obese individuals see a physical performance for the first week of transition.
A survey in 2005 of 88 paediatric neurologists in the US found that 36% regularly prescribed the diet after three or more drugs had failed, 24% occasionally prescribed the diet as a last resort, 24% had only prescribed the diet in a few rare cases, and 16% had never prescribed the diet. Several possible explanations exist for this gap between evidence and clinical practice.[34] One major factor may be the lack of adequately trained dietitians, who are needed to administer a ketogenic diet programme.[31]
Ketones are also a cleaner-burning fuel than carbs. They’re burned for energy in the mitochondria, and fewer free radicals (a highly-reactive, short-lived uncharged molecule) are generated when compared to burning glucose.15 What’s more, ketone molecules themselves cause a decrease in production of free radicals,21,22 while also increasing glutathione–a powerful antioxidant protecting against mitochondrial damage induced by free radicals.23
The Dr. Formulated Keto line of products is fully transparent, compliant to the keto guidelines and designed to be convenient—we’ve done the math for you—just mix. Crafted for those seeking to enter into ketosis or stick to a low-carbohydrate diet for weight loss and health purposes, all Dr. Formulated products are Keto Certified, Paleo Friendly and clean: Non-GMO Project Verified and Truly Grass Fed.

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]
Ken, not 100% sure I understand your question but if you're asking if you should take any more supplements through out the week, it's hard to know without getting some blood testing done. If you want to go into detail, book a consult at bengreenfieldfitness.com/coaching and choose 20 or 60 mins and we'll get you scheduled. If you want to know specifically about fueling for your runs, have a read through this: https://bengreenfieldfitness.com/2013/07/what-…

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.
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.
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?
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