Children who discontinue the diet after achieving seizure freedom have about a 20% risk of seizures returning. The length of time until recurrence is highly variable, but averages two years. This risk of recurrence compares with 10% for resective surgery (where part of the brain is removed) and 30–50% for anticonvulsant therapy. Of those who have a recurrence, just over half can regain freedom from seizures either with anticonvulsants or by returning to the ketogenic diet. Recurrence is more likely if, despite seizure freedom, an electroencephalogram shows epileptiform spikes, which indicate epileptic activity in the brain but are below the level that will cause a seizure. Recurrence is also likely if an MRI scan shows focal abnormalities (for example, as in children with tuberous sclerosis). Such children may remain on the diet longer than average, and children with tuberous sclerosis who achieve seizure freedom could remain on the ketogenic diet indefinitely.[46]
When you eat less than 50 grams of carbs a day, your body eventually runs out of fuel (blood sugar) it can use quickly. This typically takes 3 to 4 days. Then you’ll start to break down protein and fat for energy, which can make you lose weight. This is called ketosis. It's important to note that the ketogenic diet is a short term diet that's focussed on weight loss rather than the pursuit of health benefits. 
Cramps: Due to the initial release of water when starting a keto diet for beginners, people often forget to replenish and hydrate. Due to this, some may experience “dry mouth.” An effective remedy is to ensure that there is sufficient consumption of water coupled with electrolyte balance. If dehydration persists, an increase in electrolytes may be needed (especially magnesium).
Blood Lipids on a Ketogenic Diet: Lack of proper education has incorrectly held a high-fat diet responsible for an increase in blood lipids. Decades of research, combined with efforts to shift the paradigm, are now revealing that increased dietary fat consumption does not directly result in increased blood lipids. It is actually carbohydrate consumption that tends to increase total cholesterol with noticeable decreases in the HDL “good” cholesterol. Often, researchers use a “high-fat diet” interchangeably with a “Western diet;” many confuse the term “high-fat diet” in the research with a ketogenic diet. A “high-fat diet” in the research indicates a diet with both high-fats and high-carbs, which is associated with increased blood lipids, whereas a ketogenic diet is not.
Keto-adaptation occurs as tissues maximally increase their capacity to utilize ketone bodies for fuel. As glucose metabolism slows and fatty acid breakdown ramps up, ketones are synthesized and increasingly utilized for fuel. After a few weeks or months of increasing ketone and fat utilization, the body adapts to these new fuel sources. In addition to increased fat breakdown and ketone synthesis and utilization, keto-adaptation is associated with decreased and stabilized blood glucose levels.
Cravings: As one begins to eliminate carbohydrates from the diet, it is common to experience carbohydrate cravings. Several suggestions for conquering these cravings are outlined below. However, it should be noted that as the body keto-adapts, hunger and appetite should become suppressed. One interesting study found that when you increase the occupied volume inside of the stomachs of subjects, this led to feelings of perceived fullness.[17] This means by doing things like drinking more water and eating more high volume foods we can improve our feeling of fullness.
Because the ketogenic diet alters the body's metabolism, it is a first-line therapy in children with certain congenital metabolic diseases such as pyruvate dehydrogenase (E1) deficiency and glucose transporter 1 deficiency syndrome,[35] which prevent the body from using carbohydrates as fuel, leading to a dependency on ketone bodies. The ketogenic diet is beneficial in treating the seizures and some other symptoms in these diseases and is an absolute indication.[36] However, it is absolutely contraindicated in the treatment of other diseases such as pyruvate carboxylase deficiency, porphyria, and other rare genetic disorders of fat metabolism.[9] Persons with a disorder of fatty acid oxidation are unable to metabolise fatty acids, which replace carbohydrates as the major energy source on the diet. On the ketogenic diet, their bodies would consume their own protein stores for fuel, leading to ketoacidosis, and eventually coma and death.[37]
Supplemental ketosis: This form of ketosis has recently gained momentum in the field of ketogenic dieting. Supplemental ketosis is a ketogenic state that is achieved through the ingestion of ketogenic supplements. Consuming these substances alone does not mean that an individual is “keto-adapted.” While these products can help during the keto-adaptation period, especially if one is experiencing the “keto-flu,” they will only elicit short-term increases in blood ketone levels. Exogenous ketones can acutely produce benefits similar to the ketogenic diet; however, these products are best used in conjunction with a well-formulated keto diet for beginners, or the very at least, a diet that restricts carbohydrates. The commonly used supplements on the market are medium-chain triglyceride (MCT) oil and exogenous ketones. MCT oil is a fat that, in contrast to other longer-chain fatty acids, travels straight from the intestines to the liver where it is readily metabolized. This allows for ketone production in the liver to occur faster than with other fats (long-chain fatty acids have to travel through the lymph and circulatory systems first). Exogenous ketones are synthetic substances that mimic the ketones produced in our body (endogenous ketones). Exogenous ketones can come in the form of ketone salts or ketone esters.
But people who started following the keto diet noticed weight loss for a few reasons: When you eat carbs, your body retains fluid in order to store carbs for energy (you know, in case it needs it). But when you’re not having much in the carb department, you lose this water weight, says Warren. Also, it's easy to go overboard on carbohydrates—but if you're loading up on fat, it may help curb cravings since it keeps you satisfied.
It seems strange that a diet that calls for more fat can raise “good” cholesterol and lower “bad” cholesterol, but ketogenic diets are linked to just that. It may be because the lower levels of insulin that result from these diets can stop your body from making more cholesterol. That means you’re less likely to have high blood pressure, hardened arteries, heart failure, and other heart conditions. It's unclear, however; how long these effects last.
Endurance Performance: Traditionally, endurance athletes tend to consume a high amount of carbohydrates in order to “fill up” their fuel stores (i.e. glycogen) for competitions. Thus, a diet where carbohydrates are restricted seems counter-intuitive for these individuals. However, Dr. Jeff Volek’s research showed that once an individual is keto-adapted, not only is their performance the same or better than those consuming high levels of carbohydrates, but their glycogen “fuel stores” are the same as well.[11] Despite consuming a diet lower in carbohydrates, these athletes are able to adapt and utilize a nearly limitless supply of fat as their primary fuel source.
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 was inferior to studies on children. Health issues include high levels of low-density lipoprotein, high total cholesterol, and weight loss.[24]
After about two to seven days of following the keto diet, you go into something called ketosis, or the state your body enters when it doesn't have enough carbs for your cells to use for energy. That's when you start making ketones, or organic compounds that your bod then uses in place of those missing carbs. At this point, your body also starts burning fat for more energy, says Beth Warren, RD, founder of Beth Warren Nutrition and author of Living A Real Life With Real Food.
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