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]
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]
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.[56]
While it’s true that low-carb diets do raise the so-called bad LDL-cholesterol in some people, it’s important to note that LDL-C, when influenced by diet, has never been shown to have any effect on cardiovascular risk. Large clinical trials and observational studies show that one’s level of LDL-C and the lowering of LDL-C through diet is not reliably linked to cardiovascular outcomes.21, 22, 23
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)?
Dr. Campos, it is so discouraging to see that you disparage the ketogenic diet based on your assumption that it is very heavy in poor quality processed meats. No diet that relies on processed foods can be viewed as “healthy”. Become better informed by getting up to speed with what Jeff Volek, RD, PhD, calls a “well-formulated ketogenic diet.” Also, learn more about the potential of the diet to slow cancer progression (my specialty). You owe it to your patients who are depending on you for advice. Present them with facts, not opinions.
The Johns Hopkins Hospital protocol for initiating the ketogenic diet has been widely adopted.[43] It involves a consultation with the patient and their caregivers and, later, a short hospital admission.[19] Because of the risk of complications during ketogenic diet initiation, most centres begin the diet under close medical supervision in the hospital.[9]
The ketogenic diet is indicated as an adjunctive (additional) treatment in children and young people with drug-resistant epilepsy.[26][27] It is approved by national clinical guidelines in Scotland,[27] England, and Wales[26] and reimbursed by nearly all US insurance companies.[28] Children with a focal lesion (a single point of brain abnormality causing the epilepsy) who would make suitable candidates for surgery are more likely to become seizure-free with surgery than with the ketogenic diet.[9][29] About a third of epilepsy centres that offer the ketogenic diet also offer a dietary therapy to adults. Some clinicians consider the two less restrictive dietary variants—the low glycaemic index treatment and the modified Atkins diet—to be more appropriate for adolescents and adults.[9] A liquid form of the ketogenic diet is particularly easy to prepare for, and well tolerated by, infants on formula and children who are tube-fed.[5][30]
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.
On your keto food list, stick to low-glycemic sweeteners to avoid spikes in blood sugar, and avoid fillers and binders such as maltodextrin and dextrose, which can spike blood sugar and contain sneaky carbs. Sugar alcohols such as maltitol or xylitol may read as no sugar on a label, but be aware that they will still cause moderate glycemic response when digested.
^ 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.
Normal dietary fat contains mostly long-chain triglycerides (LCTs). Medium-chain triglycerides (MCTs) are more ketogenic than LCTs because they generate more ketones per unit of energy when metabolised. Their use allows for a diet with a lower proportion of fat and a greater proportion of protein and carbohydrate,[18] leading to more food choices and larger portion sizes.[4] The original MCT diet developed by Peter Huttenlocher in the 1970s derived 60% of its calories from MCT oil.[15] Consuming that quantity of MCT oil caused abdominal cramps, diarrhea, and vomiting in some children. A figure of 45% is regarded as a balance between achieving good ketosis and minimising gastrointestinal complaints. The classical and modified MCT ketogenic diets are equally effective and differences in tolerability are not statistically significant.[9] The MCT diet is less popular in the United States; MCT oil is more expensive than other dietary fats and is not covered by insurance companies.[18]
The remaining calories in the keto diet come from protein — about 1 gram (g) per kilogram of body weight, so a 140-pound woman would need about 64 g of protein total. As for carbs: “Every body is different, but most people maintain ketosis with between 20 and 50 g of net carbs per day,” says Mattinson. Total carbohydrates minus fiber equals net carbs, she explains.
Even hibernating bears do not go into ketosis[2]. And predatory animals who undergo extended periods of food deprivation, such as elephant seals[3], are metabolically resistant to ketosis; instead, they have upregulated gluconeogenesis pathways through which they can steadily produce glucose. This makes perfect sense, since predators’ survival depends on their ability to catch their prey, which usually requires intense bursts of activity. And sprinting capacity is dependent on glucose, as humans who adopt a ketogenic diet quickly discover.

Keto is not hard to follow at all. See, this is why I took my diet and nutrition into my own hands. I have PCOS and the ketogenic diet has worked wonders for me. I’m finally pregnant at the age of 32 and after 11 years of marriage because the ketogenic diet made me lose over 100 lbs and brought my insulin resistance under control. I feel better than I’ve ever felt. Sometimes doctors don’t seem to know as much as they should, or as much as they assume they do, and that’s pretty disturbing. Just like they’re still using the old school and very inaccurate BMI charts that are just pure bs. I’ll just take care of myself outside of certain situations involving illness or injury. I’m doing great on my own.
Here’s the real kicker: the reason why the Inuit don’t go into ketosis as readily as other ethnic groups is the high prevalence of a deleterious mutation in the CPT1A gene.[14] This mutation permitted adaptation to a high fat, low carbohydrate diet in the sense that those carrying the gene could survive to reproductive age while eating a diet entirely at odds with our evolutionary history. However this gene is associated with high infant mortality rates due to hypoketotic hypoglycemia: when Inuit babies’ blood glucose levels drop, they are unable to utilize ketone bodies to sustain their brains. The very mutation that permits adult survival in extreme circumstances compromises infant health – a powerful example of the trade-offs inherent to evolution. Humans can indeed adapt to an extreme environment and an extreme diet, but that adaptation comes at a high cost.
Normal dietary fat contains mostly long-chain triglycerides (LCTs). Medium-chain triglycerides (MCTs) are more ketogenic than LCTs because they generate more ketones per unit of energy when metabolised. Their use allows for a diet with a lower proportion of fat and a greater proportion of protein and carbohydrate,[18] leading to more food choices and larger portion sizes.[4] The original MCT diet developed by Peter Huttenlocher in the 1970s derived 60% of its calories from MCT oil.[15] Consuming that quantity of MCT oil caused abdominal cramps, diarrhea, and vomiting in some children. A figure of 45% is regarded as a balance between achieving good ketosis and minimising gastrointestinal complaints. The classical and modified MCT ketogenic diets are equally effective and differences in tolerability are not statistically significant.[9] The MCT diet is less popular in the United States; MCT oil is more expensive than other dietary fats and is not covered by insurance companies.[18]
First, that study, which was reported upon widely, was on mice. Mice are not like humans in the way they fatten or contract metabolic diseases. Journalists/media should stop reporting on mice stories as if they were applicable to humans, especially when there is such a large body of clinical trial data on humans. Let’s be clear: rigorous clinical trial data on humans trumps any data on mice. Every time. And what does the rigorous data on humans say?
Reduced hunger. Many people experience a marked reduction in hunger on a keto diet. This may be caused by an increased ability of the body to be fueled by its fat stores. Many people feel great when they eat just once or twice a day, and may automatically end up doing a form of intermittent fasting. This saves time and money, while also speeding up weight loss.
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