The ketogenic diet is not a benign, holistic, or natural treatment for epilepsy; as with any serious medical therapy, complications may result.[28] These are generally less severe and less frequent than with anticonvulsant medication or surgery.[28] Common but easily treatable short-term side effects include constipation, low-grade acidosis, and hypoglycaemia if an initial fast is undertaken. Raised levels of lipids in the blood affect up to 60% of children[38] and cholesterol levels may increase by around 30%.[28] This can be treated by changes to the fat content of the diet, such as from saturated fats towards polyunsaturated fats, and if persistent, by lowering the ketogenic ratio.[38] Supplements are necessary to counter the dietary deficiency of many micronutrients.[18]

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]


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]
The ketogenic diet is a mainstream dietary therapy that was developed to reproduce the success and remove the limitations of the non-mainstream use of fasting to treat epilepsy.[Note 2] Although popular in the 1920s and '30s, it was largely abandoned in favour of new anticonvulsant drugs.[1] Most individuals with epilepsy can successfully control their seizures with medication. However, 20–30% fail to achieve such control despite trying a number of different drugs.[9] For this group, and for children in particular, the diet has once again found a role in epilepsy management.[1][10]
A small Feb. 20, 2017, study looked at the impact of a six-week ketogenic diet on physical fitness and body composition in 42 healthy adults. The study, published in the journal Nutrition & Metabolism, found a mildly negative impact on physical performance in terms of endurance capacity, peak power and faster exhaustion. Overall, researchers concluded, “Our findings lead us to assume that a [ketogenic diet] does not impact physical fitness in a clinically relevant manner that would impair activities of daily living and aerobic training.” The “significant” weight loss of about 4.4 pounds, on average, did not affect muscle mass or function.

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.
Probably, and there are a few reasons why the keto diet usually equals weight-loss gold, says Keatley. For starters, people usually reduce their daily caloric intake to about 1,500 calories a day because healthy fats and lean proteins make you feel fuller sooner—and for a longer period of time. And then there’s the fact that it takes more energy to process and burn fat and protein than carbs, so you're burning slightly more calories than you did before. Over time, this can lead to weight loss.
To get the most benefit from the Keto diet, you should stay physically active. You might need to take it easier during the early ketosis period, especially if you feel fatigued or lightheaded. Walking, running, doing aerobics, weightlifting, training with kettlebells or whatever workout you prefer will boost your energy further. You can find books and online resources on how to adapt Keto meals or snacks for athletic training.
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]

Wondering what fits into a keto diet — and what doesn’t? “It’s so important to know what foods you’ll be eating before you start, and how to incorporate more fats into your diet,” says Kristen Mancinelli, RD, author of The Ketogenic Diet: A Scientifically Proven Approach to Fast, Healthy Weight Loss, who is based in New York City. We asked her for some guidelines.
Meat – like grass-fed selections – and fresh veggies are more expensive than most processed or fast foods. What you spend on Keto-friendly foods will vary with your choices of protein source and quality. You can select less-expensive, leaner cuts of meat and fatten them up with some oil. Buying less-exotic, in-season veggies will help keep you within budget.
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.
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]

But the physiological impact of low carb wasn’t even my biggest concern about the diet. I asked Craig how he recommends people cope with the social isolation brought on by hyper-specific dietary restrictions. See, food is communal; grandparents cook traditional dishes for their families, friends opt to share a large pizza or pitcher of beer, and so on. Keto doesn’t really allow for spontaneous cheat meals. Craig responded, “I think dietary restrictions are becoming commonplace in today's world,” and then talked exclusively about how restaurant menus can be tweaked.


^ Jump up to: a b c d e f g h i j k l m n o p q r s Kossoff EH, Zupec-Kania BA, Amark PE, Ballaban-Gil KR, Bergqvist AG, Blackford R, et al. Optimal clinical management of children receiving the ketogenic diet: recommendations of the International Ketogenic Diet Study Group. Epilepsia. 2009 Feb;50(2):304–17. doi:10.1111/j.1528-1167.2008.01765.x. PMID 18823325
Here’s what we do know: The keto diet may be useful in treating symptoms of epilepsy, a seizure disorder. “The use of keto in treating epilepsy has the most evidence,” Angelone says. One study conducted by Johns Hopkins Medicine, for example, followed epileptic patients on the keto diet and found that 36 percent of them had a 50 percent reduction in seizures after three months on the diet, and 16 percent were seizure-free. However, experts aren't entirely sure why the keto diet has this affect, she adds.
For the keto gurus who serve as keto's staunchest evangelicals, conversations swirl around oft-repeated talking points, and any sense of negativity is quickly batted away. I spoked to several "gurus.” The claims they made are already on most low-carb blogs: It’s gonna suck at first, but it’s Worth It. Fat makes you full. Blood sugar will go down. Insulin will be on point. You’ll realize that which has sat dormant in your body for too long -- a demigod. Devoid of carbs, your body will reconstruct in such a way that Zeus descended from parted clouds to congratulate you on your blood test results.
Stock up: Jet.com's new City Grocery service (available in select markets) makes it easy to ensure you always have keto-friendly veggies in the fridge. We love their delivery scheduling tool; simply fill your cart, then decide which day and timeframe you'd like your groceries delivered. One of our faves: Urban Roots Green Squash Veggie Noodles are great for whipping up low-carb "pasta" dishes.
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]

Lots of apps and websites offer keto diet challenges—basically, a blueprint for the keto diet with a fixed starting and ending point (they typically last for a week to a month, though some may be longer). Speaking of apps, plenty of keto-centric ones are right at your fingertips (a.k.a., your smartphone), like the KetoDiet app, which can help you calculate your macros and track your keto diet effectively.
Make things yourself. While it’s extremely convenient to buy most things pre-made or pre-cooked, it always adds to the price per pound on items. Try prepping veggies ahead of time instead of buying pre-cut ones. Try making your stew meat from a chuck roast. Or, simply try to make your mayo and salad dressings at home. The simplest of things can work to cut down on your overall grocery shopping.

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]
There are so many tricks, shortcuts, and gimmicks out there on achieving optimal ketosis – I’d suggest you don’t bother with any of that. Optimal ketosis can be accomplished through dietary nutrition alone (aka just eating food). You shouldn’t need a magic pill to do it. Just stay strict, remain vigilant, and be focused on recording what you eat (to make sure your carb and protein intake are correct).

Children who discontinue the diet after achieving seizure freedom have about a 20% risk of seizures returning. The length of time until recurrence is highly variable, but averages two years. This risk of recurrence compares with 10% for resective surgery (where part of the brain is removed) and 30–50% for anticonvulsant therapy. Of those who have a recurrence, just over half can regain freedom from seizures either with anticonvulsants or by returning to the ketogenic diet. Recurrence is more likely if, despite seizure freedom, an electroencephalogram shows epileptiform spikes, which indicate epileptic activity in the brain but are below the level that will cause a seizure. Recurrence is also likely if an MRI scan shows focal abnormalities (for example, as in children with tuberous sclerosis). Such children may remain on the diet longer than average, and children with tuberous sclerosis who achieve seizure freedom could remain on the ketogenic diet indefinitely.[46]


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]

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]
The ketogenic diet is usually initiated in combination with the patient's existing anticonvulsant regimen, though patients may be weaned off anticonvulsants if the diet is successful. Some evidence of synergistic benefits is seen when the diet is combined with the vagus nerve stimulator or with the drug zonisamide, and that the diet may be less successful in children receiving phenobarbital.[18]
"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."
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.
Keto is short for ketogenic. If you didn’t already know, it’s a high-fat, low-carb diet. The goal of the ketogenic diet is to get your body into a “ketogenic state,” or a physiological state in which your body is not burning carbohydrates -- which break down to glucose -- but an alternative energy source called ketones, which are produced by the liver when your body is depleted of glucose. Ketones are formed from fat stores. In order for your body to start producing ketones, it needs to first run out of glycogen stores. After you deprive your body of carbs, it takes a bit of time for the glucose to clear out.
The Johns Hopkins Hospital protocol for initiating the ketogenic diet has been widely adopted.[43] It involves a consultation with the patient and their caregivers and, later, a short hospital admission.[19] Because of the risk of complications during ketogenic diet initiation, most centres begin the diet under close medical supervision in the hospital.[9]

Meanwhile, more than 70 trials have examined the health effects of a low-carb diet. They attest to the benefits64 associated with ketosis and low-carb diets, including a reduction in body weight and body mass index, improved cardiovascular risk factors including blood pressure, and the reversal of Type 2 diabetes. It is virtually impossible to imagine that a diet with so many health improvements in the ‘near term’ (2 years) could ultimately shorten life—and the study authors offer no possible mechanism to explain how this might happen.


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.
The popular low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come with the same risks if you overdo it on fats and proteins and lay off the carbs. So why do people follow the diets? "They're everywhere, and people hear anecdotally that they work," McManus says. Theories about short-term low-carb diet success include lower appetite because fat burns slower than carbs. "But again, we don't know about the long term," she says. "And eating a restrictive diet, no matter what the plan, is difficult to sustain. Once you resume a normal diet, the weight will likely return."
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