Ketosis is an adaptive state that allowed our ancestors to survive temporary food shortages. When food was not available at all, or the only food available was extremely low in energy (such as leaves and grasses), their bodies could start to break down their body fat reserves after a couple of days. Ketone bodies were generated as a result allowing them to sustain their brains and preserve their muscle and other vital proteins.
No animal on earth lives permanently in ketosis. Omnivorous animals such as bears and dogs, and obligate carnivores such as cats – the ultimate low-carbers – use gluconeogenesis to transform amino acids from protein into glucose[1]. This allows them to maintain optimal blood glucose levels to fulfill their bodies’ needs for this vital nutrient. Only in prolonged starvation or a diabetic state will these animals enter ketosis.
A systematic review in 2018 looked at 16 studies on the ketogenic diet in adults. It concluded that the treatment was becoming more popular for that group of patients, that the efficacy in adults was similar to children, the side effects relatively mild. However, many patients gave up with the diet, for various reasons, and the quality of evidence inferior to studies on children. Health issues include high levels of low-density lipoprotein, high total cholesterol, and weight loss.[24]
The keto diet changes the way your body converts food into energy. Eating a lot of fat and very few carbs puts you in ketosis, a metabolic state where your body burns fat instead of carbs for fuel. When your body is unable to get glucose from carbs, your liver converts fatty acids from your diet into ketones, an alternative source of energy. Burning ketones in place of glucose reduces inflammation and spurs weight loss.[1]
Our human ancestors did not consume high-fat, low-carbohydrate diets and therefore would not have been in diet-induced ketosis. Even the most successful early hunters could not possibly have consumed enough fat to enter ketosis since african wildlife such as wildebeests, warthogs and impalas all have low body fat – well under 10%, and as low as 0.3%[6] in the dry season.
A ketogenic diet is a very low-carbohydrate way of eating that delivers moderate amounts of high-quality dietary protein and high amounts of healthy dietary fat. This reduction in carbohydrate intake helps the body shift toward a state that promotes the breakdown of fats (from the diet and your body) to produce ketone bodies and enter a state known as “ketosis.”
Over 8–10 mmol/l: It’s normally impossible to get to this level just by eating a keto diet. It means that something is wrong. The most common cause by far is type 1 diabetes, with severe lack of insulin. Symptoms include feeling very sick with nausea, vomiting, abdominal pain and confusion. The possible end result, ketoacidosis, may be fatal and requires immediate medical care. Learn more
In terms of weight loss, you may be interested in trying the ketogenic diet because you’ve heard that it can make a big impact right away. And that’s true. “Ketogenic diets will cause you to lose weight within the first week,” says Mattinson. She explains that your body will first use up all of its glycogen stores (the storage form of carbohydrate). With depleted glycogen, you’ll drop water weight. While it can be motivating to see the number on the scale go down (often dramatically), do keep in mind that most of this is water loss initially.
Advocates for the diet recommend that it be seriously considered after two medications have failed, as the chance of other drugs succeeding is only 10%.[9][31][32] The diet can be considered earlier for some epilepsy and genetic syndromes where it has shown particular usefulness. These include Dravet syndrome, infantile spasms, myoclonic-astatic epilepsy, and tuberous sclerosis complex.[9][33]
I tried the keto diet a couple years ago and about 6 weeks in of following it closely I started having significant episodes of lightheadedness and anxiety like symptoms. The coach I was working with said it was keto flu so I continued on the diet for a couple more weeks but it was making life difficult so I stopped. Now every time I try to go low carb the symptoms come back. Sometimes I wonder if it’s just anxiety response or all in my head. I would love to eat low carb but haven’t ever been able to figure out why this happens. I read somewhere that keto can be harder for women’s bodies and affect their adrenal glands. Would this increase anxiety symptoms.
Metagenics offers a wide range of educational opportunities including webinars, group meetings, and seminars as part of our commitment to continuing functional medicine education. Our goal is to give our practitioners further insight to help address their patients’ unique health needs for a higher level of personalized, lifetime wellness care. We have been sharing this ever-growing body of nutritional and lifestyle research for over 25 years.

There are three essential components of all food: fats, carbohydrates and protein. The ketogenic diet is a carefully prescribed ratio of fats to carbohydrates and protein. This ratio causes the body to convert fat into substances called ketone bodies (thus the name). These ketones are then used for fuel in many cells of the body, including the brain. When this happens, the brain goes into a higher energy state and is better able to protect itself against seizures.
Some keto cookies or a keto brownie can certainly be delicious, but if you’re looking for a dessert that’s a little more interesting, then you have to try this chocolate chia pudding! I love chia seeds for a number of reasons. They’re high in antioxidants, vitamins such as calcium, potassium and magnesium, Omega-3 ALA, dietary fiber and even protein. So, while this dish feels like a dessert, you’re receiving plenty of necessary nutrients. Enjoy guilty-free!
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.[18] 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] Some evidence indicates that adolescents and adults may also benefit from the diet.[9]
For many people, one of the more surprising side effects of starting a ketogenic diet is a bout with the “keto flu.” How so? “When you go on this diet, your kidneys don’t retain as much salt or water, which can lead to flu-like symptoms, such as fatigue and headache, or constipation,” says Laura Saslow, PhD, an assistant professor at the University of Michigan School of Nursing. “But these are typically short-lived symptoms that can be prevented or treated by increasing your salt and water intake.” However, if you have high blood pressure, speak with your doctor before adding more sodium to your diet. And know that the keto flu only lasts a week or two; symptoms typically subside once the body adjusts to the diet.
A: The most common ways to track your carbs is through MyFitnessPal and their mobile app. You cannot track net carbs on the app, although you can track your total carb intake and your total fiber intake. To get your net carbs, just subtract your total fiber intake from your total carb intake. I have written an article on How to Track Carbs on MyFitnessPal.

A ketogenic diet is high in fat and low in carbohydrates. It’s called “ketogenic” because people on this diet shift from using glucose (a type of sugar) as their main fuel source to ketone bodies, which are derived from fat. In other words, people on the ketogenic diet can use their bodies’ fat stores as fuel—and this is why many studies show that this diet is superior for sustainable weight loss.
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The keto diet is one of the most effective that I’ve come across and one of the more straightforward (as opposed to easy!) to follow. In a nutshell, when you’re on a keto diet, you eat a very low-carb, high-fat diet. That means goodbye pasta and bread, hello cheese and oils. It’s pretty much the opposite of what we’ve been taught our entire lives. But it works if you follow the keto diet food list. Plus, you can make many favorite recipes keto-friendly.
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]

The modified Atkins diet reduces seizure frequency by more than 50% in 43% of patients who try it and by more than 90% in 27% of patients.[18] Few adverse effects have been reported, though cholesterol is increased and the diet has not been studied long term.[48] Although based on a smaller data set (126 adults and children from 11 studies over five centres), these results from 2009 compare favourably with the traditional ketogenic diet.[18]

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).
This may require a lifestyle change for many families, so we advise families who are interested in the diet to learn more by reading some of our excellent printed resources and to talk to each person who regularly cares for the child to make sure there is agreement to try the diet. We usually encourage an appointment with one of our epileptologists to confirm that the diet is right for your child, and then an appointment with our ketogenic diet team to go over more of the details.
A ketogenic diet is high in fat and low in carbohydrates. It’s called “ketogenic” because people on this diet shift from using glucose (a type of sugar) as their main fuel source to ketone bodies, which are derived from fat. In other words, people on the ketogenic diet can use their bodies’ fat stores as fuel—and this is why many studies show that this diet is superior for sustainable weight loss.
While many health care providers aren’t comfortable recommending the keto diet for people with diabetes, there’s a substantial body of research indicating that it can help with weight loss, reduce the need for medication, and even lower A1C into the non-diabetes range. It’s so effective that when researchers assigned 349 volunteers with type 2 diabetes to follow either a keto diet or a traditional diabetes eating plan (the makeup of that plan wasn’t defined in the study) for one year, they observed some powerful results. While the people on the “diabetes diet” didn’t experience any positive movement in their A1C, body weight, or medication requirements, those on the keto plan reduced their A1C from 7.6 to 6.3 percent, shed 12 percent of their body weight, eliminated their need for sulfonylurea medication, and lowered or reduced their need for insulin by 94 percent. The results were published in 2018 in the journal Diabetes Therapy.
Despite its explosive popularity, there’s a lot of confusion about what the ketogenic (keto) diet really is. “Many people think they’re following a keto diet when they’re really just consuming a low-carbohydrate diet,” says Patti Urbanski, MEd, RD, CDE, a certified diabetes educator with St. Luke’s Hospital in Duluth, Minnesota. “So one person’s ‘keto diet’ may look very different than another’s.”

Missing Nutrients. One of the biggest concerns for dietitians is the keto diet’s lack of key foods. Many question the eating plan’s impact on the development of certain chronic diseases. Without milk, for example, getting enough calcium and vitamin D for sturdy bones becomes a challenge. Take away whole grains, fruit, beans, and potatoes, and it’s nearly impossible to consume enough potassium for healthy blood pressure or enough fiber to stay regular. And unless you’re eating lots of low-carb, leafy green vegetables, you miss out on vitamins A, C, K, and folate, too.  

These affect your brain and spine, as well as the nerves that link them together. Epilepsy is one, but others may be helped by a ketogenic diet as well, including Alzheimer’s disease, Parkinson’s disease, and sleep disorders. Scientists aren’t sure why, but it may be that the ketones your body makes when it breaks down fat for energy help protect your brain cells from damage.
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