Luella Klein had her first seizure at 13 months and was prescribed antiseizure medication. But by the time she was two and a half, the drugs had stopped working and she had developed new symptoms, including a severely imbalanced gait.

During a visit to the Columbia University Medical Center in New York City, Luella underwent a spinal tap to measure glucose levels in her cerebral spinal fluid. Based on the results, she was diagnosed with glucose transporter type 1 deficiency syndrome (Glut1 DS), a genetic metabolic disorder that occurs when glucose, a sugar in the blood, doesn't reach the brain in levels high enough to be used for fuel. That lack of fuel disrupts brain growth and function and can cause a variety of symptoms, including seizures, movement disorders, speech problems, and developmental delays.

Luella's doctors recommended that she be put on the ketogenic diet, a high-fat, low-carbohydrate regimen that is standard care for Glut1 DS because it provides an alternate source of fuel—fat—for the glucose-starved brain.

Fats for Fuel

Normally, the body converts the carbohydrates in food into glucose, which then becomes fuel for all parts of the body, including the brain. On the ketogenic diet, which restricts carbs and loads up the fat, a different mechanism kicks in: The liver converts fat into fatty acids and ketone bodies, chemicals that "can cross the blood-brain barrier and be used as fuel and may even be anticonvulsant," explains Eric H. Kossoff, MD, a professor of neurology and pediatrics and medical director of the Ketogenic Diet Center at Johns Hopkins Hospital in Baltimore, MD, and a member of the American Academy of Neurology (AAN). When the body is actively breaking down fat into ketone bodies, which is measured by a simple urine test, a person is said to be "in ketosis."

To initiate the diet, Luella was hospitalized for five days. Hospitalization makes it easier to determine when a patient is in ketosis and gives doctors an opportunity to educate parents and patients about the diet, says Dr. Kossoff. While there, Luella was fed meals that adhered to a strict three-to-one ratio of fat versus protein and carbohydrates. For example, a meal that contained 1 gram of carbohydrates and 2 grams of protein required 9 grams of fat.

"Within two days of being in ketosis, Luella's balance, coordination, and walking had noticeably improved, and within a month of being on the diet, her seizures had ceased," recalls Renee Klein, Luella's mother.

Now five years old, Luella remains free of seizures thanks to her daily adherence to a high-fat diet that includes plenty of cream and butter.

How Ketones Affect Seizures

For years, doctors have observed that epileptic seizures, which are triggered by abnormal electrical discharges in the brain, often diminish when patients fast. Researchers have linked this phenomenon to ketonemia, a condition induced by fasting that occurs when the body produces ketones as the brain shifts from using sugar, its preferred source of energy, to using fat. That metabolic shift seems to disrupt the abnormal discharges in the brain.

"You are forcing the brain to use a different fuel," explains Judith Bluvstein, MD, a pediatric epileptologist, an assistant professor of neurology at Epilepsy Center" href="https://nyulangone.org/locations/comprehensive-epilepsy-center" target="_blank" rel="noopener">New York University (NYU) Langone Comprehensive Epilepsy Center, and member of the AAN. "We don't know exactly how it works, but it's almost as though the brain can't figure out how to produce seizures using this new energy pathway."

Evolution of a Diet

The shift from fasting to an actual diet was rooted in research by Russell M. Wilder, MD, a physician from the Mayo Clinic in Rochester, MN, who wondered if the ketonemia produced by fasting could be activated in a different way. In 1921, he tested a high-fat, low-carb regimen on epilepsy patients and observed a reduction in seizures that equaled that of fasting. A colleague at the clinic, M.G. Peterman, MD, published a study in the Journal of the American Medical Association in 1925 reporting a significant improvement in seizure activity in 50 percent of patients adhering to the diet. Coined the "ketogenic diet," the regimen quickly became standard treatment for epileptic seizures. People with epilepsy and their caregivers were trained to follow a strict ratio of protein and carbohydrates to fats: 1 gram of protein per kilogram of body weight, 10 to 15 grams of carbohydrates per day, and the remaining calories in fat.

The diet fell out of favor as more effective antiseizure medications were introduced, but in the past few decades it has regained popularity as a treatment for children like Luella Klein whose seizures fail to respond to medication. Over the years, new variations on the diet have emerged, including a modified Atkins diet, a medium-chain-triglycerides (MCT) version, and a low glycemic index diet. "These variations evolved to help patients adhere to a more liberal version of the diet," says Courtney Schnabel Glick, a registered dietitian coordinator at NYU Langone Comprehensive Epilepsy Center.

Adapting the Diet

The classic ketogenic diet pioneered by Dr. Wilder is considered the gold standard for people with medication-resistant epilepsy because it produces the most ketones. It also demands the highest fat intake and is often the most difficult to follow due to the strict ratios required in planning and preparing meals. In Luella's case, she had to follow a three-to-one ratio of fat to carbs and proteins. So, for example, if a meal included 12.8 grams of protein (less than three ounces of meat) and 7.9 grams of carbohydrates (one cup of string beans), it would also have to include 62.1 grams of fat (roughly equal to four and a half tablespoons of butter, cream, and coconut oil), says Klein. Achieving these exact proportions requires meal preparers to weigh and measure food for every meal.

That's not the case with the modified Atkins diet. "It relies much more on keeping track of and not going over low daily carbohydrate allotments [no more than 10 grams of carbs]," says Glick. People on the MCT diet get their fat from medium-chain-triglycerides, a type of fatty acid that occurs naturally in some oils, which is also available as a liquid called MCT oil. Those who follow the low glycemic index diet eat foods with higher fiber content that don't spike blood sugar.

"All variations, if properly followed, put the body into a state of ketosis, which seems to be the key factor in reducing seizures," says Glick. The results can be dramatic. That was the experience of Kristin Mon, whose daughter Madeline, now seven, had seizures that were rapidly escalating in frequency. After two medications failed to control her daughter's seizures, Mon started Madeline on the modified Atkins diet at the recommendation of Dr. Bluvstein. Within a week of going into ketosis, Madeline no longer had convulsive seizures.

Maintaining the diet was challenging for Mon, who says it took several months to get into a groove. "It involved a lot of planning and special ingredients, some of which we had never cooked with before." Luckily, getting Madeline to comply was relatively easy, says Mon, despite having to cut her fruit consumption to 10 raspberries a day.

It Works for Adults, Too

Although traditionally used for children with epilepsy, ketogenic diets are becoming more popular with adults, says Dr. Kossoff. It has made a big difference for 30-year-old Caroline Reilly, an office administrator in Spring Lake Heights, NJ, who was diagnosed with epilepsy as an infant. After experiencing problems with various traditional drugs, Reilly started the modified Atkins diet a year ago as a patient at the NYU Langone Comprehensive Epilepsy Center.

"Until you're on the diet, you don't realize how many carbohydrates you eat," says Reilly, whose daily carbohydrate maximum was initially capped at 20 grams. Within a month of being in ketosis, she went from 10 to 20 seizures a month to less than half of that. Today, still on medication, she has almost no seizures. Whenever she feels like cheating, Reilly says, she reminds herself that the diet is not a sacrifice. It's a change in lifestyle. Seeing the huge improvement in her health also helps to keep her on track, she says.

Ketogenic Caveats

These diets do not work for everyone and should not be undertaken lightly, says Dr. Bluvstein. "It's not a natural diet, and we're not meant to eat this way unless it's medically necessary."

Some doctors will take a child off the diet if there's been no real benefit within six months. Danielle McBrian, MD, a child neurologist who specializes in epilepsy, always cautions parents about the need for medical supervision, especially since most people with metabolic epilepsy, such as Glut 1 DS, will have to be on the diet for the rest of their lives.

"No patient or caregiver should implement any version of the ketogenic diet by him or herself," says Dr. McBrian, who is also an assistant professor of neurology and director of the Ketogenic Diet Program at Columbia University Medical Center and a member of the AAN. "There may be serious interactions with commonly used seizure medications, and the side effects of the diet must also be monitored."

The side effects can be numerous and serious, says Dr. Kossoff. "The diet may cause constipation, acidosis [when the body produces more acid than the kidneys can remove, which can cause rapid breathing, confusion, going into shock, and even death], an increase in cholesterol, weight loss, kidney stones, poor growth, and bone fractures," he says. "Children and adults on the diet need to be followed very closely." Epileptologists should collaborate with clinical dietitians trained in the use of high-fat diets who can screen for early signs of diet-related side effects, says Dr. Bluvstein.

Worth the Risks

Despite the risks, uncontrolled seizures, especially in young children, are reason enough for many parents and caregivers to embrace the diet. "In most cases, parents, many of whom are well informed and have done their research, are demanding the diet," says Dr. Bluvstein. "That parents are thinking out of the box is a good thing because over the course of a lifetime, the cumulative effect of seizures can impair health."

Renee Klein says what's most important is that Luella understands why she eats this way. "I tell her that everyone's body works in different ways, and that hers works better when she eats lots of fat," she says. And Kristin Mon encourages Madeline, who's aware of why she's on it, to share her new foods with her classmates. "We tell her, your diet is something that makes you unique."

Kid-Friendly Recipe Tips

Every parent of a finicky eater knows how hard it is to get a child to eat what you prepare. Put your child on the ketogenic diet, and the challenge can be overwhelming. We asked parents who have had success with the diet to share their secrets.

• Cozy up to cream. Heavy cream is extraordinarily versatile, says Renee Klein, whose daughter Luella has a metabolic type of epilepsy and follows the classic ketogenic diet. She often adds a few berries to make it into a colorful whipped topping, and, depending on the carbohydrate count, may spoon it over low-glycemic fruit. Adding a small amount of pesto, made with high-fat additions such as pecans or Brazil nuts, turns cream into a savory sauce.
• Make mayo the main dish. Transform mayonnaise sauces and dips into the focus of a meal. Klein does it by adding a speck of mustard for flavor and serving a dish of mayo with cucumber sticks and tomatoes.
• Refashion chicken nuggets. Although breadcrumbs are a high-carb no-no, ketogenic diet veterans know how to create a respectable crispy crust. Klein shreds chicken breasts, gives them a coating of egg whites and almond flour, and cooks them in butter. "The more you can get these meals to look like the fast food your children's friends eat, the less marginalized your child will feel when she opens her lunch box," she says. Kristin Mon, whose daughter Madeline has epilepsy and is on the modified Atkins diet, dips chicken wings in butter and rolls them in grated parmesan cheese. "We put butter on everything," says Mon.
• Simplify sweet treats. Klein adds coarsely ground high-fat nuts to melted baker's chocolate, butter, and a tiny amount of stevia, spreads the mixture on a tray, then pops it into the freezer. She even bought an ice cream maker to create sugar-free and low-carb treats. "I didn't want Luella to miss out on anything other kids eat," she says. Mon, meanwhile, is a fan of flourless cake items that use flaxseed meal, protein powder, eggs, and sugar-free vanilla or fruit syrup. Another option is to look for no-bake desserts and use spices like vanilla, turmeric, cinnamon, cardamom, and nutmeg to liven up more basic recipes.
• Find inspiration online. To get ideas for potential recipes, Mon often browses low-carbohydrate diet websites. "These recipes already have the low-carb factor in place, and all I need to do is substitute," she says. She also spends "hours on Pinterest," where she has found ideas for meals from images, then determines the ingredient ratios herself. "The site really expanded my options," she says. For menu ideas and sample recipes, check out these suggestions. 
• Invite your foodie friends on board. When Mon first implemented the ketogenic regimen, her close friends organized a network of parents to cook and bake a wide variety of meals and treats for Madeline. "My daughter could test many items I wouldn't have had the time to prepare myself, and I could then replicate the winners," says Mon.

6 Ways to Ensure Success

The key to the success of the ketogenic diet is sticking to it, and that can be tough for both children and their caregivers. Here is some expert advice for keeping your eyes on the prize.

1. Stay positive. Parents are often initially enthusiastic about starting the diet but balk when hearing the details, says Danielle McBrian, MD, a pediatric epileptologist, director of the Ketogenic Diet Program at Columbia University Medical Center in New York, and a member of the American Academy of Neurology (AAN). "They are so shocked by all the fat and [the thought] that their child may be eating butter wrapped in bacon," she says.
2. Hang in there. Some parents mistakenly believe the regimen doesn't need to be followed too closely. They think "it's just a diet," says Courtney Schnabel Glick, a registered dietitian coordinator at New York University (NYU) Langone Comprehensive Epilepsy Center. When the going gets tough, she says, focus on your child's health. Remind yourself (and your child) of how well the diet is working to control the seizures when other methods have failed. Renee Klein, whose daughter Luella has a metabolic type of epilepsy, says to think of it as another medication. "When your child is taking medication, you have to track dosage and the time of administering the medicine to comply," she says. Similarly, with the ketogenic diet you have to keep track of portions and calculate fat-to-protein-and-carb ratios.
3. Seek out support. Connect with other families who have used the diet successfully, says Glick. A good place to start is the Charlie Foundation for Ketogenic Therapies, which was established 21 years ago by Jim Abrahams and counts Eric H. Kossoff, MD, as a board member. "The foundation almost singlehandedly brought the ketogenic diet into popular therapy for pediatric epilepsy," says Dr. Kossoff, a professor of neurology and pediatrics and medical director of the Ketogenic Diet Center at Johns Hopkins Hospital in Baltimore, MD, and a member of the AAN. Abrahams' son Charlie was diagnosed with difficult-to-control seizures as an infant and became seizure-free at the age of two after following the diet. That experience prompted Abrahams to provide a one-stop-shop of up-to-date information about the diet and other food-related therapies that could benefit children with epilepsy and other neurologic disorders. The organization's event series, KetoConnect, also sponsors the biennial Global Symposium on Ketogenic Therapies.
4. Reach out to teaching hospitals. "See if they offer an epilepsy program," since many of them can help implement the diet, Dr. McBrian advises. The Charlie Foundation offers links to hospitals.
5. Tune in to your tweens. When they're younger, children are often much more disciplined about the diet than they're given credit for. However, as they get older, they may become less vigilant. "They start to drop their guard," says Judith Bluvstein, MD, a pediatric epileptologist, an assistant professor of neurology at NYU Langone Comprehensive Epilepsy Center, and a member of the AAN. She recalls a 10-year-old boy who had done so well with the diet after two years that he no longer needed to be on medication. "Then, one day, out of the blue, he told me, 'I get these food temptations,'" she says. Not long after that, the child's mother received a phone call from his school. "The boy had gone to the cafeteria kitchen during off-hours, pushed a quarter into the cook's palm, and said, 'Give me a piece of bread,'" says Dr. Bluvstein. "Young people can become desperate for variety from the same monotonous menu." But a piece of bread could trigger seizures, she cautions. "Those seizures can last until the person returns to his or her previous level of ketosis."
6. Don't forget the details. Everything your child ingests has to be calculated for the ketogenic diet, including medication and even toothpaste, both of which contain sugar. Forgetting that can throw off the carbohydrate count, says Dr. Bluvstein. "This could lead to sudden new seizures, which might lead parents to believe the diet failed." Parents typically rely on calorie-counting websites or smartphone apps to gauge carb, fat, and protein content, says Glick. For parents who adapt recipes from websites, Dr. McBrian advises reviewing them with a registered dietitian who can calculate the ratios more precisely and help parents tweak the recipes to meet the nutritional requirements to remain in ketosis.