For patients who benefit, half achieve a seizure reduction within five days (if the diet starts with an initial fast of one to two days), three-quarters achieve a reduction within two weeks, and 90% achieve a reduction within 23 days. If the diet does not begin with a fast, the time for half of the patients to achieve an improvement is longer (two weeks), but the long-term seizure reduction rates are unaffected.[44] Parents are encouraged to persist with the diet for at least three months before any final consideration is made regarding efficacy.[9]
The word diet first appeared in English in the 13th century. Its original meaning was the same as in modern English, “habitually taken food and drink.” But diet was used in another sense too in the Middle and early modern English periods to mean “way of living.” This is, in fact, the original meaning of diet’s Greek ancestor diaita, which is derived from the verb diaitasthan, meaning “to lead one’s life.” In Greek, diaita, had already come to be used more specifically for a way of living prescribed by a physician, a diet, or other regimen.
The interesting thing is that many people are willing to spend a lot of time, money, and energy on expensive gym memberships and boutique fitness classes—and then say they’re too busy to cook. Even if you only spend 15 minutes driving to and from the gym every day, that’s 30 minutes that you could have put toward cooking a healthy dinner. And if you spend $30 a pop, 3 times per week on fancy circuit or spin classes, that’s $90 you could dedicate to your grocery budget. That wild salmon doesn’t sound quite so outrageous now, right?

Live It! This phase is a lifelong approach to diet and health. In this phase, you learn more about food choices, portion sizes, menu planning, physical activity, exercise and sticking to healthy habits. You may continue to see a steady weight loss of 1 to 2 pounds (0.5 to 1 kilogram) a week until you reach your goal weight. This phase can also help you maintain your goal weight permanently.


The fact that the group following both the exercise and diet programs showed the greatest benefit suggests that the two interventions may work together to improve brain health, Blumenthal says. “We saw evidence that exercise and the diet together are better than nothing,” he says. “We showed you can get improvements in function that can reduce and certainly improve neurocognitive function, and possibly even postpone development of dementia late in life.”


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]
All of the men and women in the study were sedentary when they started the study, and while they showed signs of cognitive decline, they did not have dementia. They also had at least one heart-disease related risk factor. Researchers know that heart health, and how well blood circulates throughout the body and brain, is important to maintaining cognitive skills, since the brain relies on oxygen–rich blood to fuel its activities.

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.
The researchers agree that the diet itself isn’t inherently dangerous. But, cautions Weiss, “If you have any medical condition, if you take any medicine at all – there are lots of things that change how medicines work in our bodies, and nutrition is definitely one of them. If you’re making a real change in your nutrition, you really should talk to your doctor.”
Information on this website is provided for informational purposes only and is not intended as a substitute for the advice provided by your physician or other healthcare professional. You should not use the information on this website for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment. Any third party offering or advertising on this website does not constitute an endorsement by Andrew Weil, M.D. or Healthy Lifestyle Brands.
Health.com is part of the Meredith Health Group. All rights reserved. The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments. All products and services featured are selected by our editors. Health.com may receive compensation for some links to products and services on this website. Offers may be subject to change without notice. See the Terms of Servicethis link opens in a new tab and Privacy Policythis link opens in a new tab (Your California Rightsthis link opens in a new tab)for more information. Ad Choicesthis link opens in a new tab | EU Data Subject Requeststhis link opens in a new tab

^ Freeman JM, Vining EP, Pillas DJ, Pyzik PL, Casey JC, Kelly LM. The efficacy of the ketogenic diet—1998: a prospective evaluation of intervention in 150 children. Pediatrics. 1998 Dec;102(6):1358–63. doi:10.1542/peds.102.6.1358. PMID 9832569. https://web.archive.org/web/20040629224858/http://www.hopkinsmedicine.org/press/1998/DECEMBER/981207.HTM Lay summary]—JHMI Office of Communications and Public Affairs. Updated 7 December 1998. Cited 6 March 2008.
"The keto diet is primarily used to help reduce the frequency of epileptic seizures in children. While it also has been tried for weight loss, only short-term results have been studied, and the results have been mixed. We don't know if it works in the long term, nor whether it's safe," warns registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital.
The interesting thing is that many people are willing to spend a lot of time, money, and energy on expensive gym memberships and boutique fitness classes—and then say they’re too busy to cook. Even if you only spend 15 minutes driving to and from the gym every day, that’s 30 minutes that you could have put toward cooking a healthy dinner. And if you spend $30 a pop, 3 times per week on fancy circuit or spin classes, that’s $90 you could dedicate to your grocery budget. That wild salmon doesn’t sound quite so outrageous now, right?
When Hadid goes out for breakfast, she ups the ante. “I live near The Smile, and I love their scrambled eggs, bacon, and toast,” she also told Harper’s Bazaar. Turoff says that the model is likely getting uncured, grass-fed pork at the upscale spot, so the bacon is probably not as bad an option as it might initially seem (there’s a potential concern about processed meat like bacon causing cancer, per the World Health Organization). Still, Palumbo advises that you consider bacon a “once in a while” order rather than an everyday item.
The strategy worked for people whether they followed diets that were mostly low in fat or mostly low in carbohydrates. And their success did not appear to be influenced by their genetics or their insulin-response to carbohydrates, a finding that casts doubt on the increasingly popular idea that different diets should be recommended to people based on their DNA makeup or on their tolerance for carbs or fat.

“A lot of people think the foundation of a paleo diet is high-fat meat, but I suggest that it’s vegetables,” says Hultin. The concept is to eat only foods — including meat, fish, poultry, eggs, fruits, and vegetables — that would have been available to our Paleolithic ancestors. This means grains, dairy, legumes, added sugar, and salt are all no-no’s.
×