The ketogenic diet is a high-fat eating plan that severely restricts carbohydrates, typically to 50 grams per day or less. For reference, many dietary associations recommend adults get 200 to 300 grams of carbohydrates per day. By limiting carbohydrates, the ketogenic diet shifts your body from relying on glucose (sugar) to fat for energy. After the body has run out of stored glucose, it starts to convert fat into an energy source called ketone bodies, or ketones, producing a state in the body called ketosis. Many people with epilepsy find that running on ketones instead of glucose provides better seizure control.
However, ketogenic diet therapies aren’t for everyone. Medical supervision is essential, especially when you’re first starting out. Ketogenic diets are highly restrictive and can produce side effects in children, teens, and adults with epilepsy. Rather than a first line of treatment of epilepsy or something you should experiment with on your own, ketogenic diets are typically seen as a last resort that requires the ongoing support of your health care team.
The MyEpilepsyTeam message boards are filled with people who live with epilepsy sharing their questions about and experiences with a ketogenic diet. One member asked, “Has anyone ever tried the ketogenic diet to help stop having seizures? I don’t want to keep taking more medication, and in the future, I want to have more children, but my doctor said I would need to stop taking the medication I am on now. I would like to try this as an alternative to meds.”
So is the ketogenic diet a cure-all for epilepsy? Here is the latest research, along with real-life stories from MyEpilepsyTeam members.
A classic ketogenic diet requires specific ratios of the three macronutrients: carbohydrates, protein, and fat. In the ketogenic diet, up to 90 percent of calories should come from fat. Protein and carbohydrates should make up no more than 10 percent of total caloric intake, with about 4 percent from carbohydrates and 6 percent from protein.
Sticking to a ketogenic diet can be complicated, especially at first. Meeting with a dietitian who specializes in ketogenic diets is essential to making sense of the numbers and translating the guidelines into a realistic meal plan.
The types of foods encouraged on a ketogenic diet include:
Lean meats and low-fat dairy products tend to be too high in protein to meet the ratio of fat to carbohydrates necessary for a classic ketogenic diet. You’ll need to limit all grain foods, beans, starchy vegetables (like potatoes), and high-sugar fruits (like bananas) to stay within a ketogenic range. Although fried foods are high in fat, those prepared with flour tend to contain too many carbohydrates to fit a ketogenic diet. Eliminating sugary beverages and desserts is an essential part of the keto diet.
One-third of people with epilepsy eventually develop drug resistance, meaning their medications stop controlling their seizures. For these individuals, the ketogenic diet may be a suitable alternative with promising effects — but the ketogenic diet is often viewed as a “last resort” treatment, not something to be undertaken lightly. The ketogenic diet works by exerting multiple effects on the brain that can be helpful for seizure prevention. It helps brain cells (neurons) function better under stress, and it reduces the excess firing of neurons. Ketogenic diets may also favorably change gut bacteria for those with epilepsy.
Studies show that the ketogenic diet effectively halves seizure frequency in 40 percent to 67 percent of pediatric epilepsy cases. More research on adults is needed, but preliminary data suggests a similar level of seizure reduction in adults and children. Although all types of epilepsy (including refractory epilepsy) may improve on a ketogenic diet, generalized epilepsy seems to be the most responsive.
Variations of the ketogenic diet, such as the modified Atkins diet (MAD) and the low glycemic index treatment (LGIT), may be preferred if you have trouble with a classic ketogenic diet. Traditional ketogenic diets must be started in the hospital, but MAD and LGIT can be started at home. Nonetheless, it is still recommended that you speak with your neurologist before beginning either of these diets. MAD and LGIT allow you to eat more carbohydrates and protein, making them much less restrictive — however, their effectiveness is still being studied. It’s even possible to do a vegetarian ketogenic diet, although you may find the limited variety of foods too restrictive to adhere to long term.
Although many members of MyEpilepsyTeam look to the ketogenic diet as a replacement for seizure medication, others see it as a supplement to their current treatment plan. One member shared, “You definitely don’t want to make dramatic or sudden changes because then you’re just inviting seizures. Even the implementation or starting with the ketogenic diet is a process. … The main attribute of the keto diet is that it introduces more stability throughout the body.”
However, a ketogenic diet can also interfere with certain medications. Although most medications are safe and effective on a ketogenic diet, this diet may interfere with certain antiepileptic drugs. Speak to your doctor before starting the ketogenic diet if you are taking zonisamide (Zonegran) or topiramate (Topamax), especially if you are at risk for kidney stones. One clinical trial determined that children on a ketogenic diet who took topiramate had a significantly decreased bicarbonate level compared to children not on a ketogenic diet. Therefore, people on the ketogenic diet who are taking topiramate must be monitored for metabolic acidosis (increased acid produced by the body) and kidney damage.
Make sure to speak to your doctor before starting the ketogenic diet, and tell your doctor about your diet before starting a new medication. Do not stop taking medication without the advice of a doctor.
A common side effect of the ketogenic diet is weight loss. This process is not totally understood, but it may be due in part to a decrease in appetite and water weight. Most people will also go through a temporary period called the “keto flu” — with headache, dizziness, and stomach upset — as their body adjusts to relying on ketones (a product of broken-down fatty acids) as a primary fuel source. Eventually, the hormonal effects of the ketogenic diet can reduce your appetite and increase satiety (the feeling of fullness), causing you to eat less. While this may be beneficial for some, it’s essential to keep your health care team aware of how your body is changing. You may need to adjust your medications after starting a keto diet.
Gastrointestinal side effects are also common on the ketogenic diet. They could include constipation, diarrhea, vomiting, hunger, stomach pain, and altered taste. Other possible side effects include fatigue, nutrient deficiencies, osteoporosis, gout, kidney stones, and gallstones. A condition called ketoacidosis is also a rare, but potentially dangerous, effect of low-carbohydrate diets in some individuals.
The restrictive nature of ketogenic diets can make it difficult to get enough of certain nutrients, which can cause some individuals to stop the eating plan early. Having the guidance of a health care professional will help you do keto the right way. Be sure to find vegetables and some fruits that are low in carbohydrates but that provide you with adequate fiber, vitamins, and minerals to prevent constipation or nutrient deficiencies. You could also consider a vitamin and mineral supplement. Drinking plenty of water may help you avoid side effects like constipation, kidney stones, and gallstones.
The ketogenic diet can present a problem for people who are underweight or for growing children and infants. Your health care team should monitor you to make sure you are reaping benefits from the diet and not compromising other key markers, like nutrient sufficiency, growth, and bone density. Children should be on the diet for no longer than two years, doctors say, but many adults with epilepsy choose to maintain a ketogenic diet for life.
There’s lots of talk about the ketogenic diet on MyEpilepsyTeam — both positive and negative. One member mentions their positive experience with this diet: “I’ve been on keto for a year. If I cheat, I seize. It’s just that simple. Cheating on the diet causes a spike in blood sugar, and I seize within 24 hours. I am on strict keto and haven’t been on medication for over a year. I have partial complex seizures. Perhaps it is a type of seizure that responds better to the diet; I do not know. Keto allows me to live my life again without fear.” The ketogenic diet also worked well for this member: “I was introduced in my teens to the ketogenic diet by Dr. Atkins himself for the treatment of my allergies. Its side benefit was that it helped slow down the metabolism of sugar/carbohydrates, as I was borderline hypoglycemic at the time. It also made my seizures less frequent, as they were between meals or late at night when my blood sugar was low.”
However, not everyone is a fan of the ketogenic diet. One member said: “It doesn’t work for everyone because they tried that with me as a kid and it didn’t help at all. … When you go through ketosis, you’re gonna feel really sick. Just talk to your doctor and a nutritionist.” Another MyEpilepsyTeam member shared their negative experience: “I tried keto for three months and didn’t see a difference. … I started doing yoga three times a week, stopped eating meat and dairy about 90 percent of the time, started eating carbs, and continued avoiding sugar, and my seizures went down tremendously. … I think yoga helped way more than any diet I’ve ever tried has.”
Always discuss changes to your treatment and lifestyle with your neurologist. It may seem like adjusting your diet isn’t a big deal, but for someone with epilepsy, switching to keto can have a significant impact.
MyEpilepsyTeam is the social network for people with epilepsy and their loved ones. On MyEpilepsyTeam, more than 112,000 members come together to ask questions, give advice, and share their stories with others who understand life with epilepsy.
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