A ketogenic diet is high in fat and low in carbohydrates. It’s called “ketogenic” because people on this diet shift from using glucose (a type of sugar) as their main fuel source to ketone bodies, which are derived from fat. In other words, people on the ketogenic diet can use their bodies’ fat stores as fuel—and this is why many studies show that this diet is superior for sustainable weight loss.

A study with an intent-to-treat prospective design was published in 1998 by a team from the Johns Hopkins Hospital[20] and followed-up by a report published in 2001.[21] As with most studies of the ketogenic diet, no control group (patients who did not receive the treatment) was used. The study enrolled 150 children. After three months, 83% of them were still on the diet, 26% had experienced a good reduction in seizures, 31% had had an excellent reduction, and 3% were seizure-free.[Note 7] At 12 months, 55% were still on the diet, 23% had a good response, 20% had an excellent response, and 7% were seizure-free. Those who had discontinued the diet by this stage did so because it was ineffective, too restrictive, or due to illness, and most of those who remained were benefiting from it. The percentage of those still on the diet at two, three, and four years was 39%, 20%, and 12%, respectively. During this period, the most common reason for discontinuing the diet was because the children had become seizure-free or significantly better. At four years, 16% of the original 150 children had a good reduction in seizure frequency, 14% had an excellent reduction, and 13% were seizure-free, though these figures include many who were no longer on the diet. Those remaining on the diet after this duration were typically not seizure-free, but had had an excellent response.[21][22]
My point here is that the warnings about the ketogenic principles are well taken and well documented. My concern is implications that this is a fad. I don’t use the word diet with my patients and I’m concerned that the principles behind the label and the real results that these readers have commented on might get minimized. I have found it best to encourage patients to read authors like: Stephen Phinney, Jeff Volek, Patricia Daly, and Charles Gant and the be partners with their doctors and check blood work as they move along. I am not for or against the article. If ketogenic principles offer people enduring, satisfying, and cohesive change then why not read about its potential and flexilbity?
I have been on a low carb keto diet for more than a year. As T2DM my A1C dropped from 9% to 5.4% & I discontinued meds. All my lipids improved even with ample healthy saturated fat. More than a year now so I wonder why this would be a short term improvement when its obvious that I will not go back to a high A1C and taking 3 diabetes medications including sulphonylureas. It is clear from this article that you lack the necessary experience that would be gained from wholeheartedly trying the diet or monitoring patients doing it properly like me. I would be probably be facing my first amputation if I believed the negativity in your article. So for people with diabetes who may be dissuaded by your article. Ignore it and take back your health by restricting carbs (<25 g a day) or as low as you reasonably can below 130g while being satisfied that you are getting adequate nutrition.
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]
Recently, many of my patients have been asking about a ketogenic diet. Is a ketogenic diet safe? Would you recommend it? Despite the recent hype, a ketogenic diet is not something new. In medicine, we have been using it for almost 100 years to treat drug-resistant epilepsy, especially in children. In the 1970s, Dr. Atkins popularized his very-low-carbohydrate diet for weight loss that began with a very strict two-week ketogenic phase. Over the years, other fad diets incorporated a similar approach for weight loss.
Articles and information on this website may only be copied, reprinted, or redistributed with written permission (but please ask, we like to give written permission!) The purpose of this Blog is to encourage the free exchange of ideas. The entire contents of this website is based upon the opinions of Dave Asprey, unless otherwise noted. Individual articles are based upon the opinions of the respective authors, who may retain copyright as marked. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the personal research and experience of Dave Asprey and the community. We will attempt to keep all objectionable messages off this site; however, it is impossible to review all messages immediately. All messages expressed on The Bulletproof Forum or the Blog, including comments posted to Blog entries, represent the views of the author exclusively and we are not responsible for the content of any message.
Weight loss is the primary reason my patients use the ketogenic diet. Previous research shows good evidence of a faster weight loss when patients go on a ketogenic or very low carbohydrate diet compared to participants on a more traditional low-fat diet, or even a Mediterranean diet. However, that difference in weight loss seems to disappear over time.

Alison Moodie is a health reporter based in Los Angeles. She has written for numerous outlets including Newsweek, Agence France-Presse, The Daily Mail and HuffPost. For years she covered sustainable business for The Guardian. She holds a master’s degree from Columbia University’s Graduate School of Journalism, where she majored in TV news. When she's not working she's doting on her two kids and whipping up Bulletproof-inspired dishes in her kitchen.
Ketosis and the subsequent metabolic state associated with it has been shown to have positive effects on chronic conditions, from PCOS to type 2 diabetes. Just a few weeks of eating keto recipes and keeping your blood sugar stable results in improved energy, elevated mood, and possibly best of all, quick weight loss. It’s not uncommon for people to drop 10 pounds or more in the first couple of weeks while sticking with a keto diet!
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]
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]
For many people, one of the more surprising side effects of starting a ketogenic diet is a bout with the “keto flu.” How so? “When you go on this diet, your kidneys don’t retain as much salt or water, which can lead to flu-like symptoms, such as fatigue and headache, or constipation,” says Laura Saslow, PhD, an assistant professor at the University of Michigan School of Nursing. “But these are typically short-lived symptoms that can be prevented or treated by increasing your salt and water intake.” However, if you have high blood pressure, speak with your doctor before adding more sodium to your diet. And know that the keto flu only lasts a week or two; symptoms typically subside once the body adjusts to the diet.

When your body burns its stores of fat, it can be hard on your kidneys. And starting a ketogenic diet -- or going back to a normal diet afterward -- can be tricky if you’re obese because of other health issues you’re likely to have, like diabetes, a heart condition, or high blood pressure. If you have any of these conditions, make diet changes slowly and only with the guidance of your doctor.
The idea that ketosis is human beings’ natural state is also contradicted by the heavy dependence of human embryonic and fetal development on glucose. All women become insulin resistant during normal pregnancy[15] as glucose is directed toward the developing baby. Pregnant women deprived of carbohydrates are at high risk of developing ketoacidosis in later pregnancy.[16] This dangerous condition can occur as the nutrient needs of the developing fetus reach their peak and drive up maternal ketone production.
Metagenics offers a wide range of educational opportunities including webinars, group meetings, and seminars as part of our commitment to continuing functional medicine education. Our goal is to give our practitioners further insight to help address their patients’ unique health needs for a higher level of personalized, lifetime wellness care. We have been sharing this ever-growing body of nutritional and lifestyle research for over 25 years.
A keto diet has shown to improve triglyceride levels and cholesterol levels most associated with arterial buildup. More specifically low-carb, high-fat diets show a dramatic increase in HDL and decrease in LDL particle concentration compared to low-fat diets.3A study in the long-term effects of a ketogenic diet shows a significant reduction in cholesterol levels, body weight, and blood glucose. Read more on keto and cholesterol >
No deep fryers or air fryers needed for these wings! Forget those greasy chicken wings you’d order at a restaurant and opt-in for these homemade guiltless garlic parmesan wings. You won’t find rancid vegetable oil, gluten or a deep frier here — just avocado oil, healthy pecorino romano and free-range, organic chicken for a twist on an otherwise unhealthy classic.

In 1921, Rollin Turner Woodyatt reviewed the research on diet and diabetes. He reported that three water-soluble compounds, β-hydroxybutyrate, acetoacetate, and acetone (known collectively as ketone bodies), were produced by the liver in otherwise healthy people when they were starved or if they consumed a very low-carbohydrate, high-fat diet.[10] Dr. Russell Morse Wilder, at the Mayo Clinic, built on this research and coined the term "ketogenic diet" to describe a diet that produced a high level of ketone bodies in the blood (ketonemia) through an excess of fat and lack of carbohydrate. Wilder hoped to obtain the benefits of fasting in a dietary therapy that could be maintained indefinitely. His trial on a few epilepsy patients in 1921 was the first use of the ketogenic diet as a treatment for epilepsy.[10]
I tried the keto diet a couple years ago and about 6 weeks in of following it closely I started having significant episodes of lightheadedness and anxiety like symptoms. The coach I was working with said it was keto flu so I continued on the diet for a couple more weeks but it was making life difficult so I stopped. Now every time I try to go low carb the symptoms come back. Sometimes I wonder if it’s just anxiety response or all in my head. I would love to eat low carb but haven’t ever been able to figure out why this happens. I read somewhere that keto can be harder for women’s bodies and affect their adrenal glands. Would this increase anxiety symptoms.
A study with an intent-to-treat prospective design was published in 1998 by a team from the Johns Hopkins Hospital[20] and followed-up by a report published in 2001.[21] As with most studies of the ketogenic diet, no control group (patients who did not receive the treatment) was used. The study enrolled 150 children. After three months, 83% of them were still on the diet, 26% had experienced a good reduction in seizures, 31% had had an excellent reduction, and 3% were seizure-free.[Note 7] At 12 months, 55% were still on the diet, 23% had a good response, 20% had an excellent response, and 7% were seizure-free. Those who had discontinued the diet by this stage did so because it was ineffective, too restrictive, or due to illness, and most of those who remained were benefiting from it. The percentage of those still on the diet at two, three, and four years was 39%, 20%, and 12%, respectively. During this period, the most common reason for discontinuing the diet was because the children had become seizure-free or significantly better. At four years, 16% of the original 150 children had a good reduction in seizure frequency, 14% had an excellent reduction, and 13% were seizure-free, though these figures include many who were no longer on the diet. Those remaining on the diet after this duration were typically not seizure-free, but had had an excellent response.[21][22]
The classic ketogenic diet is not a balanced diet and only contains tiny portions of fresh fruit and vegetables, fortified cereals, and calcium-rich foods. In particular, the B vitamins, calcium, and vitamin D must be artificially supplemented. This is achieved by taking two sugar-free supplements designed for the patient's age: a multivitamin with minerals and calcium with vitamin D.[18] A typical day of food for a child on a 4:1 ratio, 1,500 kcal (6,300 kJ) ketogenic diet comprises three small meals and three small snacks:[28]

Because some cancer cells are inefficient in processing ketone bodies for energy, the ketogenic diet has also been suggested as a treatment for cancer.[59][60] A 2018 review looked at the evidence from preclinical and clinical studies of ketogenic diets in cancer therapy. The clinical studies in humans are typically very small, with some providing weak evidence for anti-tumour effect, particularly for glioblastoma, but in other cancers and studies, no anti-tumour effect was seen. Taken together, results from preclinical studies, albeit sometimes contradictory, tend to support an anti-tumor effect rather than a pro-tumor effect of the KD for most solid cancers.[61]
Modern-day ketogenic diet promoters such as Pete Evans advocate low-carbohydrate diets for babies and children. However, the Inuit practiced exclusive breastfeeding until their children reached 2 years of age,[11] at which time meat was introduced in their diets. In other words, at the time of most rapid brain growth, the low-carb eating Inuit provided their children with the only carbohydrate-rich food available to them – human milk.

Note: Are you a vegetarian or vegan and want to go on a ketogenic diet? It’s still possible! Just keep in mind that the dietary restrictions can sometimes be a little bit intense. Make sure to plan ahead and prepare to aid your success. To help out, we’ve published articles (with 7 day meal plans included) for both the vegetarian ketogenic diet and the vegan ketogenic diet.

Even when exercising at a submaximal level (for example, biking at a moderate speed), heart rate and adrenaline levels rise more when people are eating a high-fat, low-carbohydrate diet[4] vs. a high-carbohydrate, low-fat diet. This results in those on the high fat diet perceiving that they are working harder to achieve the same pace as the high-carbers, and they have much more difficulty speeding up their pace in sprints or climbs.


When your body burns its stores of fat, it can be hard on your kidneys. And starting a ketogenic diet -- or going back to a normal diet afterward -- can be tricky if you’re obese because of other health issues you’re likely to have, like diabetes, a heart condition, or high blood pressure. If you have any of these conditions, make diet changes slowly and only with the guidance of your doctor.
×