The keto diet is often called a fad diet. Make no mistake: it is. But unlike other trendy diets, the keto diet is unique because it actually pushes the body into an alternate, natural metabolic state called ketosis. When this happens, you can reliably expect a few negative side effects, notably those that come with the "keto flu." But other side effects emerge only when people implement the keto diet poorly, typically by failing to eat balanced, nutrient-rich foods as a part of a high-fat, low-carb diet.


Make things yourself. While it’s extremely convenient to buy most things pre-made or pre-cooked, it always adds to the price per pound on items. Try prepping veggies ahead of time instead of buying pre-cut ones. Try making your stew meat from a chuck roast. Or, simply try to make your mayo and salad dressings at home. The simplest of things can work to cut down on your overall grocery shopping.

Ketosis is a nutritional process characterised by serum concentrations of ketone bodies over 0.5 mM, with low and stable levels of insulin and blood glucose.[1][2] It is almost always generalized with hyperketonemia, that is, an elevated level of ketone bodies in the blood throughout the body. Ketone bodies are formed by ketogenesis when liver glycogen stores are depleted (or from metabolising medium-chain triglycerides[3]). Ketones can also be consumed in exogenous ketone foods and supplements.
Yes, they're technically a fruit, but we think olives deserve a shout-out all of their own, since they're also a great source of healthy fats and are one of a few keto-approved packaged foods. Plus, they're a great source of antioxidants, will satisfy your craving for something salty, and are blissfully low-carb. “About a palm's worth only has 3 grams of net carbs,” Sarah Jadin, RD, told Health in a previous interview.
C8 is the rarest MCT found in coconut oil, comprising about 6% of coconut oil. It has potent anti-microbial properties (way more potent than lauric acid) to help you maintain a healthy gut, and it is the fastest MCT to metabolize in the brain. (hence the name Brain Octane). Your liver does not need to process C8, and it only takes the steps for your body to turn it into ATP cellular energy (sugar takes 26 steps). You would need 18 tablespoons of coconut oil to get just one tablespoon of Brain Octane.
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fueling brain function. However, if little carbohydrate remains in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. An elevated level of ketone bodies in the blood, a state known as ketosis, leads to a reduction in the frequency of epileptic seizures.[1] Around half of children and young people with epilepsy who have tried some form of this diet saw the number of seizures drop by at least half, and the effect persists even after discontinuing the diet.[2] Some evidence indicates that adults with epilepsy may benefit from the diet, and that a less strict regimen, such as a modified Atkins diet, is similarly effective.[1] Potential side effects may include constipation, high cholesterol, growth slowing, acidosis, and kidney stones.[3]
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.
In nondiabetics, ketosis (also called nutritional ketosis) is regulated and controlled in the body so that ketone levels never reach the harmful levels associated with diabetic ketoacidosis. Ketoacidosis is an acute, life-threatening condition that occurs in severely uncontrolled diabetes (mainly type 1) when ketones rise to massive, supranormal levels.
In ketogenesis, two acetyl-CoA molecules instead condense to form acetoacetyl-CoA via thiolase. Acetoacetyl-CoA momentarily combines with another acetyl-CoA via HMG-CoA synthase to form hydroxy-β-methylglutaryl-CoA. Hydroxy-β-methylglutaryl-CoA form the ketone body acetoacetate via HMG-CoA lyase. Acetoacetate can then reversibly convert to another ketone body—D-β-hydroxybutyrate—via D-β-hydroxybutyrate dehydrogenase. Alternatively, acetoacetate can spontaneously degrade to a third ketone body (acetone) and carbon dioxide, although the process generates much greater concentrations of acetoacetate and D-β-hydroxybutyrate. When blood glucose levels are low, ketone bodies can be exported from the liver to supply crucial energy to the brain.[28]
The thing is, for keto to work, it can’t just be treated like any other diet, which is really confusing considering all the pundits touting the “keto diet.” Eating a balanced diet in daylight hours and night capping with a “keto bar” from Whole Foods is not going to put you in a state of ketosis, nor is eating keto religiously and bingeing the family sized bag of Doritos twice a week. Putting the word “diet” beside “keto” is a bit misleading because it downplays the outrageous restrictions required to put your body in an unnatural fat-burning state. In order to accomplish the “ketosis” most diet plans talk about, you need to radically change your lifestyle -- and, unlike switching to a balanced diet of whole foods, you must be fairly religious about carb restriction in order to reap the benefits.
^ Bechtel PJ (2 December 2012). Muscle as Food. Elsevier Science. pp. 171–. ISBN 978-0-323-13953-3. Retrieved 19 May 2014. Freezing does stop the postmortem metabolism but only at about −18ºC and lower temperatures. Above −18ºC increasing temperatures of storage cause an increasing rate of ATP breakdown and glycolysis that is higher in the comminuted meat than in the intact tissue (Fisher et al., 1980b). If the ATP concentration in the frozen tissue falls below ~ 1 µmol/g no contraction or rigor can occur because they are prevented by the rigid matrix of ice.

The ketogenic diet typically reduces carbohydrate intake to less than 50 grams per day — and calls for increased protein and fat intake, according to a review published in August 2013 in the European Journal of Clinical Nutrition. Roughly speaking, on keto you’ll get 70 to 80 percent of your calories from fat, about 20 percent from protein, and as little as 5 percent from carbs.

^ Greenberg CR, Dilling LA, Thompson GR, Seargeant LE, Haworth JC, Phillips S, Chan A, Vallance HD, Waters PJ, Sinclair G, Lillquist Y, Wanders RJ, Olpin SE (April 2009). "The paradox of the carnitine palmitoyltransferase type Ia P479L variant in Canadian Aboriginal populations". Molecular Genetics and Metabolism. 96 (4): 201–7. doi:10.1016/j.ymgme.2008.12.018. PMID 19217814.
It’s also important to note there have been no long-term studies on the ketogenic diet, nor has there been research that details what may happen to the body if it’s in a constant state of ketosis itself. But given how the body needs carbs to function properly, diets that are based on fat burning may lead to nutritional deficiencies, and supplements and multivitamins are recommended because you’re cutting out entire food groups, warns Alyssa Rothschild, RDN, who is in private practice in New York City.

Decades later, when low carb became the best thing since sliced bread, people were calling it the Air Force Diet and the Drinking Man’s; Atkins and Paleo; Comet and Cupid. Then, in 2016, podcaster and MMA commentator Joe Rogan discussed keto once on his show and his loyal following of fitness enthusiasts and life optimizers took it and ran (especially in the mornings, to increase fat burning during the fasting state). 


Note: Because you'll be excluding some major food groups on the keto diet (grains, many fruits) you should definitely think about taking a multivitamin—especially one that contains folic acid, which helps your body make new cells and is often found in enriched breads, cereals, and other grain products, says Julie Upton, R.D., cofounder of nutrition website Appetite for Health.
Ben – curious about your thoughts on this. I went into ketosis (using LOTS of coconut oil) but it raised my cholesterol and doc was worried about my lp(a) level (17mg/dL on VAP) even though crp was 0.5, trigs 51 and a1c was 5.2. Advised a low fat diet. Have you seen this before with folks on a lchf/ketosis diet and is there anything to be concerned about? Off to read your coconut oil article. Thank you! 

One proposed benefit of the ketogenic diet is that you may lose more weight compared with other diets. One study of 17 obese men found that a high-protein, low-carb ketogenic diet over a four-week period helped reduce hunger, resulting in lower food intake and more weight loss compared with a high-protein, medium-carbohydrate nonketogenic diet. (3)

But wait, there’s one loophole. Have polycystic ovary syndrome (PCOS)? Then the keto diet may help regulate your periods. “Women with PCOS have high insulin levels, which cause sex hormone imbalances,” notes Yawitz. In a small study published in the journal Nutrition & Metabolism, subjects with PCOS following a ketogenic diet for six months noted improvements in their menstrual cycles — and a small number of women became pregnant, overcoming previous infertility obstacles. “This study was very small, so we can’t make recommendations for all women with PCOS based on its findings,” says Yawitz. “And really, any diet that leads to weight loss should help in PCOS.”


I am not a doctor and this is not to be taken, interpreted or construed as medical advice. If you have poor liver or gallbladder function, it can be a good idea to take care of that prior to a high fat diet, yes. But a healthy high fat diet would not cause liver issues per se. These are just my own personal thoughts and not a prescription or a diagnosis or any form of health care whatsoever.


In the 1960s, medium-chain triglycerides (MCTs) were found to produce more ketone bodies per unit of energy than normal dietary fats (which are mostly long-chain triglycerides).[15] MCTs are more efficiently absorbed and are rapidly transported to the liver via the hepatic portal system rather than the lymphatic system.[16] The severe carbohydrate restrictions of the classic ketogenic diet made it difficult for parents to produce palatable meals that their children would tolerate. In 1971, Peter Huttenlocher devised a ketogenic diet where about 60% of the calories came from the MCT oil, and this allowed more protein and up to three times as much carbohydrate as the classic ketogenic diet. The oil was mixed with at least twice its volume of skimmed milk, chilled, and sipped during the meal or incorporated into food. He tested it on 12 children and adolescents with intractable seizures. Most children improved in both seizure control and alertness, results that were similar to the classic ketogenic diet. Gastrointestinal upset was a problem, which led one patient to abandon the diet, but meals were easier to prepare and better accepted by the children.[15] The MCT diet replaced the classic ketogenic diet in many hospitals, though some devised diets that were a combination of the two.[10]
This answer made me sad. Having lived in New York all of my life, I from a young age saw loved ones fall victim to spontaneous gluten intolerance and restaurants run to their rescue with accommodating menus.  This is why I get annoyed. What’s a dietary prescription for someone who wants to go to a dinner party and be able to eat a meal that was prepared for them? Keto is cultish not for its members’ radical commitment to a dietary restriction but for their lack of full participation in the outside world.
On the ketogenic diet I feel very shaky/anxious from when I wake up til about noon. Eating doesn’t really help. It could be electrolyte related but seems possibly more related to excess cortisol/adrenaline as noon is also when I start to crash and get tired on a more normal diet, and because those 3 am awakenings that worsen simultaneously in ketosis seem to also have to do with HPA axis stuff. Does this side effect potentially also have to do with my fasting blood sugar being elevated?
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