Josh Axe, a doctor of natural medicine and clinical nutritionist, estimates that about 25% of people who try a ketogenic diet experience these symptoms, with fatigue being the most common. “That happens because your body runs out of sugar to burn for energy, and it has to start using fat,” he says. “That transition alone is enough to make your body feel tired for a few days.”
The ketone bodies are possibly anticonvulsant; in animal models, acetoacetate and acetone protect against seizures. The ketogenic diet results in adaptive changes to brain energy metabolism that increase the energy reserves; ketone bodies are a more efficient fuel than glucose, and the number of mitochondria is increased. This may help the neurons to remain stable in the face of increased energy demand during a seizure, and may confer a neuroprotective effect.[55]
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.[3] 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] There is some evidence that adolescents and adults may also benefit from the diet.[9]
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.
Breakfast was our favorite weekend treat. We'd always go out to our diner and order all American breakfast (eggs, bacon, potatoes) and shared an order of waffles or french toast. Now, partially to save money and mostly because you can't really trust most restaurants not to add hidden carbs in things, we cook at home. Now I can't believe we used to eat all of this tasty food AND an extra stack of extras.
IF: So I thought I would try IF 16:8 this month. I just don't think this is for me at this time. The 3rd day, by the time it was time to eat, I was on the edge of a binge trigger. I could feel it bubbling up. With my past eating disorders, restriction like that becomes a trigger. I'm just not at a place yet where I feel confident in myself to do it.
The ketogenic diet is calculated by a dietitian for each child. Age, weight, activity levels, culture and food preferences all affect the meal plan. First, the energy requirements are set at 80–90% of the recommended daily amounts (RDA) for the child's age (the high-fat diet requires less energy to process than a typical high-carbohydrate diet). Highly active children or those with muscle spasticity require more calories than this; immobile children require less. The ketogenic ratio of the diet compares the weight of fat to the combined weight of carbohydrate and protein. This is typically 4:1, but children who are younger than 18 months, older than 12 years, or who are obese may be started on a 3:1 ratio. Fat is energy-rich, with 9 kcal/g (38 kJ/g) compared to 4 kcal/g (17 kJ/g) for carbohydrate or protein, so portions on the ketogenic diet are smaller than normal. The quantity of fat in the diet can be calculated from the overall energy requirements and the chosen ketogenic ratio. Next, the protein levels are set to allow for growth and body maintenance, and are around 1 g protein for each kg of body weight. Lastly, the amount of carbohydrate is set according to what allowance is left while maintaining the chosen ratio. Any carbohydrate in medications or supplements must be subtracted from this allowance. The total daily amount of fat, protein and carbohydrate is then evenly divided across the meals.[36]
My numbers come out similar to yours. I’m confused about your daily menu example, though. I figure I can only eat 70g or 2 – 3 oz of meat per day. That is one very small piece of meat. But you show meat at every meal. Also, the fat requirement is about equal to one cup of lard. How do you do that if you’re on the go and want to, say, pack a quick lunch? Or if you’re traveling?
For athletes, research on the keto diet highlights potential improvements in athletic performance, especially when it comes to endurance activities. An article suggests ketogenic-type diets may allow endurance athletes to rely mostly on stored fat for energy during exercise rather than having to refuel with simple carbohydrates during endurance training and competition while additionally improving recovery times. (10)
I have great respect for Harvard Medical School. I notice that they support their readers posting comments and I am most appreciative of the article and all the many thoughtful comments by the readers. The readers seem to have the most expertise here and I hope that the doctor who wrote the article will think long and hard about the comments by readers. After 35 years of clinical practice in mental health, I notice that all issues of emotion involve medical issues, nutrition, and the gut bacteria. I would say that these issues and all of the executive brain functions seem to improve with ketogenic principles. For those that apply it in a flexible and smart manner, it appears to improve every area of their lives. I strongly encourage the author of the article to take one class via The Institute for Functional Medicine. If he is open to more learning he can take more classes and get certified. I’m sure a fine doctor, he will be an even better doctor and personally healthier, if he gets more training. Are we all open to new learning(especially us healthcare providers)?

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.
Hello Myriam, I am a dual certified personal trainer and Sports Nutrition Specialist. I really love how concisely you have put this article together. I did notice that on your macro breakdown for a 1500 calorie diet you actually listed the protein intake at around 31% of the daily calories (117*4=468..468/1500=.31). I was wondering if you did this to bring the protein amount closer to 1 gram per pound of body-weight to preserve lean mass?
All carbs turn to sugar in your body but some people can handle eating sweet potatoes or regular potatoes and not have any craving issues. I just look at them and I gain weight and I crave more and more. I am very carb intolerant. The more I indulge in carbohydrates the more I want and on and on and on it goes. It’s a vicious cycle and I finally stopped the cycle. Know how? By eating keto!
“Mark is doing that keto diet,” his wife, Kelly Ripa, said on Live with Kelly and Ryan on Tuesday. “Since he’s been doing that I’ve been on a mostly carb diet. He’ll have the burger but he won’t have the bun. Then I see that little bun sitting there with burger juice on it and the condiments and yeah, I’m not a big meat eater so I just eat that bun with the lettuce and the tomato and I’m a happy camper.”
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]
Ready to head out the door and start buying groceries? Slow down there, chief. Go through the pantry, fridge, freezer, and secret stashes under the bed, and get rid of foods with any significant carb content. In the first few days, you could end up craving them—badly. This means fruit, too. Even carrots and onions are too high-glycemic to work with keto, Wittrock says.
The ketogenic diet—also known as "keto"—has become the latest big thing in weight-loss plans, touted recently by celebs like Jenna Jameson, Mama June, and Halle Berry. The diet involves cutting way back on carbohydrates, to 50 grams a day or less, to help the body achieve a state of ketosis, in which it has to burn fat (rather than sugar) for energy.

Don’t stick to chicken and steak just because you’re comfortable cooking them. Make dinner time the place where you can try new meats and recipes that increase your keto recipe resources. “At lunch and dinner, you can be creative and experiment,” Weaver says. “Just focus on cooking meat—pork, chicken, lamb, beef, or seafood. Meat is rich in iron and fish contains omega-3 fatty acids and vitamin D. Use only organic oils, such as avocado oil, coconut oil, and olive oil.”
The ketogenic diet is not a benign, holistic or natural treatment for epilepsy; as with any serious medical therapy, there may be complications.[27] These are generally less severe and less frequent than with anticonvulsant medication or surgery.[27] Common but easily treatable short-term side effects include constipation, low-grade acidosis and hypoglycaemia if there is an initial fast. Raised levels of lipids in the blood affect up to 60% of children[37] and cholesterol levels may increase by around 30%.[27] 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.[37] Supplements are necessary to counter the dietary deficiency of many micronutrients.[3]

If you talk to keto aficionados, you’ll find many save leftovers from dinner for the next day’s lunch. Cook once, eat twice—your keto diet menu for lunch is solved. If you don’t like leftovers or if you’re craving something different for lunch, the mid-day meal can be as simple as a scoop of chicken salad. Or, hit the salad bar at a local grocery store and top a bowl of greens with some good-fat goodies. You can also try one of these simple keto lunches:
Another difference between older and newer studies is that the type of patients treated with the ketogenic diet has changed over time. When first developed and used, the ketogenic diet was not a treatment of last resort; in contrast, the children in modern studies have already tried and failed a number of anticonvulsant drugs, so may be assumed to have more difficult-to-treat epilepsy. Early and modern studies also differ because the treatment protocol has changed. In older protocols, the diet was initiated with a prolonged fast, designed to lose 5–10% body weight, and heavily restricted the calorie intake. Concerns over child health and growth led to a relaxation of the diet's restrictions.[18] Fluid restriction was once a feature of the diet, but this led to increased risk of constipation and kidney stones, and is no longer considered beneficial.[3]
All of us are looking for the fastest and easiest way to achieve the body of our dreams. It can be difficult juggling a career, family, personal life and a busy schedule all while trying to achieve the body of our dreams and still maintain our sanity. Well with years of research, we have discovered that the Keto Fit Diet is the answer to our problems and allows us to maintain a healthy balance easily. You may have heard of the Keto Diet before and are probably well aware of the incredible results. We have implemented a team of healthcare professionals to create the most beneficial weight loss and nutrition methods to stop wasting time with things that simply dont work. We’ve eliminated the unnecessary hurdles of dieting and created a bare bones program that will guarantee results with the most enjoyable diet you can find. Those words usually don’t belong in the same sentence, but when youre done, you’ll agree. This is a lifestyle change that we can all enjoy. Years of research and trial and error have allowed us to come up with the most successful Keto Diet on the market with thousands of happy customers to back up these claims.
The Keto diet emphasizes weight loss through fat-burning. The goal is to quickly lose weight and ultimately feel fuller with fewer cravings, while boosting your mood, mental focus and energy. According to Keto proponents, by slashing the carbs you consume and instead filling up on fats, you safely enter a state of ketosis. That’s when the body breaks down both dietary and stored body fat into substances called ketones. Your fat-burning system now relies mainly on fat – instead of sugar – for energy. While similar in some ways to familiar low-carb diets, the Keto diet’s extreme carb restrictions – about 20 net carbs a day or less, depending on the version – and the deliberate shift into ketosis are what set this increasingly popular diet apart.
×