Even in endurance sports that don’t require sprinting, ketogenic-style diets are disadvantageous according to a ketogenic diet and exercise article published in Sports Medicine[5]: “a high-fat, low-carbohydrate ketogenic diet may impair exercise performance via reducing the capacity to utilize carbohydrates, which forms a key fuel source for skeletal muscle during intense endurance-type exercise.” The article concluded, “At present there are no data available to suggest that ingestion of ketone bodies during exercise improves athletes’ performance under conditions where evidence-based nutritional strategies are applied appropriately.”
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.
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.[19] 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.[18]
When you’ve eaten all of the crustless spinach quiche and keto frittata recipes that you can, these keto everything bagels are another great breakfast staple. With their help, you don’t have to cut out your favorite breakfast sandwiches. You can also try a bread-less keto breakfast sandwich with chicken sausage patties as the “buns” when you’re craving a keto-approved breakfast option.
Because it lacks carbohydrates, a ketogenic diet is rich in proteins and fats. It typically includes plenty of meats, eggs, processed meats, sausages, cheeses, fish, nuts, butter, oils, seeds, and fibrous vegetables. Because it is so restrictive, it is really hard to follow over the long run. Carbohydrates normally account for at least 50% of the typical American diet. One of the main criticisms of this diet is that many people tend to eat too much protein and poor-quality fats from processed foods, with very few fruits and vegetables. Patients with kidney disease need to be cautious because this diet could worsen their condition. Additionally, some patients may feel a little tired in the beginning, while some may have bad breath, nausea, vomiting, constipation, and sleep problems.
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]
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]
These chewy cookies take the same amount of prep and ingredients compared to dirty keto cookies — and the results are packed with nutrients and rich flavor. With a dough made out of almond meal, gut-loving collagen protein, cocoa powder, and melty chunks of dark chocolate, this recipe bakes up into a sinful-tasting dessert with benefits. Just 2.5 net carbs per cookie.
To minimize the risk of hypoglycemia, Yancy and his team decrease medication as soon as a patient starts the diet. While drugs like metformin and liraglutide (Victoza) are less of a concern, there are others that pose a substantial hypoglycemia threat. In addition to insulin, the sulfonylurea drugs glipizide and glyburide require a watchful eye, as they work by stimulating the pancreas to make more insulin, increasing the risk of dangerous lows in the face of insufficient carbohydrate intake. “People on this diet need to be prepared to check their blood glucose any time they feel like it could be getting too low,” says Urbanski. “I would say a minimum of twice a day, but ideally three to four times a day, at least in the beginning in order to see the effect of the diet on their blood glucose readings.”

Note the emphasis on ketosis as a temporary adaptive state. Our ancestors could not be in fasting-induced ketosis permanently because they would eventually exhaust their fat reserves (which were presumably far more limited than ours, owing to the simple fact that they ate less and moved more than we do). They would then progress from fasting to starving, and subsequently die.
In the first week, many people report headaches, mental fogginess, dizziness, and aggravation. Most of the time, this is the result of your electrolytes being flushed out, as ketosis has a diuretic effect. Make sure you drink plenty of water and keep your sodium intake up.6One of the fathers of keto, Dr. Phinney, shows that electrolyte levels (especially sodium) can become unbalanced with low carb intake.
A ketogenic diet is comprised of approximately 10% of daily calories coming from healthy carbohydrates such as leafy greens, nonstarchy vegetables, and limited amounts of legumes and berries; 20% of daily calories coming from proteins such as omega-3-rich fish and grass-fed animal protein; and ~70% of daily calories coming from high-quality fats such as avocado, unsaturated and medium-chain triglyceride oils, nuts and seeds, and coconut.
We realize that the ketogenic diet can be very demanding of children and families, so we make sure that we stay with families throughout the entire treatment. Our multidisciplinary team includes a social worker that can help your child and their siblings cope with the stresses that come with the diet. Your child will also have regular, relationship-building contact with the same team of nurses. Additionally, we have an education specialist on staff who specializes in meeting with teachers and administrators to help prepare schools for children with epilepsy.

The other nutritional remedy for T2 diabetes is carbohydrate restriction. In a large, ongoing university-based study, 60% of patients with Type 2 diabetes reversed their diagnosis of diabetes after just one year on a ketogenic diet, supplemented by support via a mobile phone app.11 On this protocol, 94% of participants reduced or eliminated their need for insulin medications while improving the vast majority of cardiovascular risk factors.12

I have been on a low carb keto diet for more than a year. As T2DM my A1C dropped from 9% to 5.4% & I discontinued meds. All my lipids improved even with ample healthy saturated fat. More than a year now so I wonder why this would be a short term improvement when its obvious that I will not go back to a high A1C and taking 3 diabetes medications including sulphonylureas. It is clear from this article that you lack the necessary experience that would be gained from wholeheartedly trying the diet or monitoring patients doing it properly like me. I would be probably be facing my first amputation if I believed the negativity in your article. So for people with diabetes who may be dissuaded by your article. Ignore it and take back your health by restricting carbs (<25 g a day) or as low as you reasonably can below 130g while being satisfied that you are getting adequate nutrition.
A ketogenic diet also has been shown to improve blood sugar control for patients with type 2 diabetes, at least in the short term. There is even more controversy when we consider the effect on cholesterol levels. A few studies show some patients have increase in cholesterol levels in the beginning, only to see cholesterol fall a few months later. However, there is no long-term research analyzing its effects over time on diabetes and high cholesterol.
Professional guidance is important in deciding whether or not the ketogenic diet is the right path based on the individual’s health history and goals, and it's also necessary to routinely monitor ketone levels in the body while on the diet. At Metagenics, we offer a number of resources to help support the ketogenic journey along with several convenient ketogenic supplementation options to help bring convenience and variety to ketogenic living.
Because some cancer cells are inefficient in processing ketone bodies for energy, the ketogenic diet has also been suggested as a treatment for cancer.[59][60] A 2018 review looked at the evidence from preclinical and clinical studies of ketogenic diets in cancer therapy. The clinical studies in humans are typically very small, with some providing weak evidence for anti-tumour effect, particularly for glioblastoma, but in other cancers and studies, no anti-tumour effect was seen. Taken together, results from preclinical studies, albeit sometimes contradictory, tend to support an anti-tumor effect rather than a pro-tumor effect of the KD for most solid cancers.[61]
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.
There are numerous benefits that come with being on keto: from weight loss and increased energy levels to therapeutic medical applications. Most anyone can safely benefit from eating a low-carb, high-fat diet. Below, you’ll find a short list of the benefits you can receive from a ketogenic diet. For a more comprehensive list, you can also read our in-depth article here >

After increasing water intake and replacing electrolytes, it should relieve most all symptoms of Keto Flu. For an average person that is starting a ketogenic diet, eating 20-30g of net carbs a day, the entire adaptation process will take about 4-5 days. My advice is to cut your carbs to fewer than 15g to ensure that you are well on your way into ketosis within one week. If you are experiencing any more keto flu symptoms, double check your electrolyte intake and adjust.

The keto diet isn’t new, and it’s been around for nearly a century. It was originally developed to treat people with epilepsy. In the 1920s, researchers found that raised levels of ketones in the blood led to fewer epileptic seizures in patients. The keto diet is still used today to treat children with epilepsy who don’t respond well to anti-epileptic drugs.[2]


A ketogenic diet could be an interesting alternative to treat certain conditions, and may accelerate weight loss. But it is hard to follow and it can be heavy on red meat and other fatty, processed, and salty foods that are notoriously unhealthy. We also do not know much about its long-term effects, probably because it’s so hard to stick with that people can’t eat this way for a long time. It is also important to remember that “yo-yo diets” that lead to rapid weight loss fluctuation are associated with increased mortality. Instead of engaging in the next popular diet that would last only a few weeks to months (for most people that includes a ketogenic diet), try to embrace change that is sustainable over the long term. A balanced, unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water seems to have the best evidence for a long, healthier, vibrant life.
No human population has ever lived in a permanent state of ketosis. Ketogenic diets are dangerous for pregnant women and developing fetuses, and the only human population that has ever subsisted on this dietary pattern advocated by keto diet proponents could only do so because of a genetic mutation that prevents them from going into ketosis. Unfortunately, it has the unintended but unavoidable consequence of reducing the survival prospects of their infants.
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.
The brain is composed of a network of neurons that transmit signals by propagating nerve impulses. The propagation of this impulse from one neuron to another is typically controlled by neurotransmitters, though there are also electrical pathways between some neurons. Neurotransmitters can inhibit impulse firing (primarily done by γ-aminobutyric acid, or GABA) or they can excite the neuron into firing (primarily done by glutamate). A neuron that releases inhibitory neurotransmitters from its terminals is called an inhibitory neuron, while one that releases excitatory neurotransmitters is an excitatory neuron. When the normal balance between inhibition and excitation is significantly disrupted in all or part of the brain, a seizure can occur. The GABA system is an important target for anticonvulsant drugs, since seizures may be discouraged by increasing GABA synthesis, decreasing its breakdown, or enhancing its effect on neurons.[7]
There are theoretically no restrictions on where the ketogenic diet might be used, and it can cost less than modern anticonvulsants. However, fasting and dietary changes are affected by religious and cultural issues. A culture where food is often prepared by grandparents or hired help means more people must be educated about the diet. When families dine together, sharing the same meal, it can be difficult to separate the child's meal. In many countries, food labelling is not mandatory so calculating the proportions of fat, protein and carbohydrate is difficult. In some countries, it may be hard to find sugar-free forms of medicines and supplements, to purchase an accurate electronic scale, or to afford MCT oils.[54]

Early studies reported high success rates; in one study in 1925, 60% of patients became seizure-free, and another 35% of patients had a 50% reduction in seizure frequency. These studies generally examined a cohort of patients recently treated by the physician (a retrospective study) and selected patients who had successfully maintained the dietary restrictions. However, these studies are difficult to compare to modern trials. One reason is that these older trials suffered from selection bias, as they excluded patients who were unable to start or maintain the diet and thereby selected from patients who would generate better results. In an attempt to control for this bias, modern study design prefers a prospective cohort (the patients in the study are chosen before therapy begins) in which the results are presented for all patients regardless of whether they started or completed the treatment (known as intent-to-treat analysis).[19]
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 helps control blood sugar levels. It is excellent for managing type 2 diabetes, sometimes even leading to complete reversal of the disease. This has been proven in studies. It makes perfect sense since keto lowers blood-sugar levels, reduces the need of medications and reduces the potentially negative impact of high insulin levels.
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