In essence, it is a diet that causes the body to release ketones into the bloodstream. Most cells prefer to use blood sugar, which comes from carbohydrates, as the body’s main source of energy. In the absence of circulating blood sugar from food, we start breaking down stored fat into molecules called ketone bodies (the process is called ketosis). Once you reach ketosis, most cells will use ketone bodies to generate energy until we start eating carbohydrates again. The shift, from using circulating glucose to breaking down stored fat as a source of energy, usually happens over two to four days of eating fewer than 20 to 50 grams of carbohydrates per day. Keep in mind that this is a highly individualized process, and some people need a more restricted diet to start producing enough ketones.
Conklin's fasting therapy was adopted by neurologists in mainstream practice. In 1916, a Dr McMurray wrote to the New York Medical Journal claiming to have successfully treated epilepsy patients with a fast, followed by a starch- and sugar-free diet, since 1912. In 1921, prominent endocrinologist Henry Rawle Geyelin reported his experiences to the American Medical Association convention. He had seen Conklin's success first-hand and had attempted to reproduce the results in 36 of his own patients. He achieved similar results despite only having studied the patients for a short time. Further studies in the 1920s indicated that seizures generally returned after the fast. Charles P. Howland, the parent of one of Conklin's successful patients and a wealthy New York corporate lawyer, gave his brother John Elias Howland a gift of $5,000 to study "the ketosis of starvation". As professor of paediatrics at Johns Hopkins Hospital, John E. Howland used the money to fund research undertaken by neurologist Stanley Cobb and his assistant William G. Lennox.[10]
One of the most-cited worries about the keto diet is the long-term impact it may have on heart health—especially because people with diabetes are at greater risk for heart disease. In the small Diabetic Medicine study that found people with type 1 improved their A1Cs on a keto diet, participants had higher triglycerides and LDL (“bad”) cholesterol. This raises concerns about the diet’s longer-term heart health implications, as do the results of research published last year in The Lancet. That study followed more than 15,000 adults for 25 years and found that people who consumed less than 40 percent of their calories from carbohydrates were significantly more likely to die from heart disease than those whose diets contained 50 to 55 percent of calories from carbs—especially if the foods that replaced those carbs were rich in animal fats and proteins.

One meta-analysis18 incorporating data from 447 participants found that low-carbohydrate diets not only helped individuals lose weight, but also improved their cholesterol. And another meta-analysis,19 citing 17 clinical trials, found that low-carb diets protected against major cardiovascular risk factors. A third study20 including 119 participants found that low-carbohydrate dieters had lower cholesterol than low-fat dieters after one year.
Look, the good doctor is right – he only forgot to stress “portion control” which is why many fanatical dieters are so kee-jerk reactive to any discussion – odds are you over ate like a hog before your keto diet, and are weak and insecure in your diet plans. Eat EVERYTHING in small amounts, and you will live long and prosper. The only thing to avoid are processed foods. Cook your meals from scratch using quality ingredients.
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.
Upon starting the diet, some patients report symptoms like fatigue, headaches, and muscle aches. However, these short-lived symptoms are, in fact, a sign that the diet is working, and the body is switching over from burning glucose as fuel to burning fat. This transition involves upregulating certain enzymes and down-regulating others; it is a profound shift for the human body that can have uncomfortable symptoms. However, these side effect usually last only 3-4 weeks. They can be ameliorated in most cases, by drinking several cups of bouillion broth during the day until the transition is completed.15
My principal hope in this article is to provide journalists with a resource to do what basic journalism demands, namely to ensure that stories are scientifically balanced and accurate. At the end of this post I provide contacts for some of the credentialed experts who helped me compile this research. Reporters, please seek out these or other low-carb diet experts so you can provide accurate, up-to-date information for your readers.

In the first week, many people report headaches, mental fogginess, dizziness, and aggravation. Most of the time, this is the result of your electrolytes being flushed out, as ketosis has a diuretic effect. Make sure you drink plenty of water and keep your sodium intake up.6One of the fathers of keto, Dr. Phinney, shows that electrolyte levels (especially sodium) can become unbalanced with low carb intake.


The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fueling brain function. However, if little carbohydrate remains in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. An elevated level of ketone bodies in the blood, a state known as ketosis, leads to a reduction in the frequency of epileptic seizures.[1] Around half of children and young people with epilepsy who have tried some form of this diet saw the number of seizures drop by at least half, and the effect persists even after discontinuing the diet.[2] Some evidence indicates that adults with epilepsy may benefit from the diet, and that a less strict regimen, such as a modified Atkins diet, is similarly effective.[1] Potential side effects may include constipation, high cholesterol, growth slowing, acidosis, and kidney stones.[3]
You won’t miss dirty keto add-ins like heavy cream or peanut butter with this recipe. Ripe strawberries and coconut milk blend into a sweet pastel shake perfect for dessert (or breakfast). Choose full-fat canned coconut milk for your dairy and get fresh, organic strawberries to make it more Bulletproof. (And enjoy chia seeds in moderation, since they can irritate your stomach.)
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]

Fanatic? Someone with T2D, a disease usually claimed to be progressive and a never ending stream of problems and medications, was REVERSED. That’s something to shout from the rooftops. The drop in medication use alone, but the big pharma companies would prefer that people’s stories of reversing (well, putting it into remission) T2D get called fanatical instead of insightful.
But even if you’re not trying to lose weight, the keto meal plans might appeal to you. By limiting sugars and processed grains, you lower your risk of type 2 diabetes. Eating an array of heart-healthy fats, like nuts, olive oil and fish, can decrease your risk of heart disease. And while some people stick to a super strict keto diet, with 75 percent of their diet coming from fat, 20 percent from protein and just five from carbs, even a less intense, modified version can help you reap the keto diet’s benefits.
Early studies reported high success rates; in one study in 1925, 60% of patients became seizure-free, and another 35% of patients had a 50% reduction in seizure frequency. These studies generally examined a cohort of patients recently treated by the physician (a retrospective study) and selected patients who had successfully maintained the dietary restrictions. However, these studies are difficult to compare to modern trials. One reason is that these older trials suffered from selection bias, as they excluded patients who were unable to start or maintain the diet and thereby selected from patients who would generate better results. In an attempt to control for this bias, modern study design prefers a prospective cohort (the patients in the study are chosen before therapy begins) in which the results are presented for all patients regardless of whether they started or completed the treatment (known as intent-to-treat analysis).[19]
Achieving ketosis is a pretty straightforward, but it can seem complicated and confusing with all of the information out there.4If you want to learn more about ketosis and the scientific process around it, you can visit a very in-depth discussion about on Dr. Peter Attia’s website. Here’s the bottom line on what you need to do, ordered in levels of importance:
The ketogenic diet reduces seizure frequency by more than 50% in half of the patients who try it and by more than 90% in a third of patients.[18] Three-quarters of children who respond do so within two weeks, though experts recommend a trial of at least three months before assuming it has been ineffective.[9] Children with refractory epilepsy are more likely to benefit from the ketogenic diet than from trying another anticonvulsant drug.[1] Some evidence indicates that adolescents and adults may also benefit from the diet.[9]

Here’s the real kicker: the reason why the Inuit don’t go into ketosis as readily as other ethnic groups is the high prevalence of a deleterious mutation in the CPT1A gene.[14] This mutation permitted adaptation to a high fat, low carbohydrate diet in the sense that those carrying the gene could survive to reproductive age while eating a diet entirely at odds with our evolutionary history. However this gene is associated with high infant mortality rates due to hypoketotic hypoglycemia: when Inuit babies’ blood glucose levels drop, they are unable to utilize ketone bodies to sustain their brains. The very mutation that permits adult survival in extreme circumstances compromises infant health – a powerful example of the trade-offs inherent to evolution. Humans can indeed adapt to an extreme environment and an extreme diet, but that adaptation comes at a high cost.


Missing Nutrients. One of the biggest concerns for dietitians is the keto diet’s lack of key foods. Many question the eating plan’s impact on the development of certain chronic diseases. Without milk, for example, getting enough calcium and vitamin D for sturdy bones becomes a challenge. Take away whole grains, fruit, beans, and potatoes, and it’s nearly impossible to consume enough potassium for healthy blood pressure or enough fiber to stay regular. And unless you’re eating lots of low-carb, leafy green vegetables, you miss out on vitamins A, C, K, and folate, too. 
So rather than giving one-size-fits-all dietary advice or weaponizing the word “balanced” it might be better if the medical community suggested that there are Individual differences that need to be considered. This might also help those lay folk who have had success with one dietary lifestyle or another also realize that what’s valid for them may not be good advice for others.

Thanks for this article. I just started a Keto diet so found it appropriate to my current lifestyle. Though I don’t believe your bottom line is strong enough since you simply stating that the diet is “hard to follow” and food is “notoriously unhealthy” without evidence going deeper into why those “notoriously unhealthy” foods are worse than keeping carbohydrate-heavy food that are addictive and give the body a quick sugar high for energy. I believe “hard to follow” is your opinion only, since acceptable Keto foods are found at all restaurants easily and also all grocery stores. All the foods you mention: “rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water” are all Keto-friendly. Many people have been on a Keto-diet for years. A healthy lifestyle is a healthy mindset change and making right choices – it’s not going to be easy.
Fuels and feeds your brain: Ketones provide an immediate hit of energy for your brain, and up to 70% of your brain’s energy needs when you limit carbs.[6] Fat also feeds your brain and keeps it strong. Your brain is at least 60% fat, so it needs loads of good fats to keep it running.[7] Essential fatty acids such as omega-3s help grow and develop the brain, while saturated fat keeps myelin — the layer of insulation around the brain — strong so your neurons can communicate with each other.

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.


Upon starting the diet, some patients report symptoms like fatigue, headaches, and muscle aches. However, these short-lived symptoms are, in fact, a sign that the diet is working, and the body is switching over from burning glucose as fuel to burning fat. This transition involves upregulating certain enzymes and down-regulating others; it is a profound shift for the human body that can have uncomfortable symptoms. However, these side effect usually last only 3-4 weeks. They can be ameliorated in most cases, by drinking several cups of bouillion broth during the day until the transition is completed.15

Because people with type 2 diabetes are at an increased risk for cardiovascular disease, there’s a specific concern that the saturated fat in the diet may drive up LDL, or “bad,” cholesterol levels, and further increase the odds of heart problems. If you have type 2 diabetes, talk to your doctor before attempting a ketogenic diet. They may recommend a different weight-loss diet for you, like a reduced-calorie diet, to manage diabetes. Those with epilepsy should also consult their doctor before using this as part of their treatment plan.
×