Slashing carbs to this degree forces the body into ketosis, a metabolic state in which your body starts to rapidly break down fat for fuel. That sounds better than it feels. During the first few days—sometimes weeks—of ketosis, people often feel tired, irritable, and dizzy and have difficulty sleeping. This carbohydrate withdrawal is often called the “keto flu,” explains registered nutritionist and certified dietitian Dana Notte, MS, director of nutrition at Green Mountain at Fox Run, a healthy-weight retreat known for helping women “detox” from fad dieting. Check out the 13 things everyone gets wrong about the keto diet.
I’m discouraged to see that nowhere in the article nor in the comments is there a mention of a diet’s best fit to genetics. Consider if someone is an APOE E2 carrier and/or has certain polymorphisms of the APO5 gene. These are quite rare in Okinawa but much more prevalent in the USA (12% of the population). According to a number of well-designed studies, these genetic characteristics point to a higher fat, lower carbohydrate diet as beneficial and even a “moderate” carb diet as problematic.
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.
Around this time, Bernarr Macfadden, an American exponent of physical culture, popularised the use of fasting to restore health. His disciple, the osteopathic physician Dr. Hugh William Conklin of Battle Creek, Michigan, began to treat his epilepsy patients by recommending fasting. Conklin conjectured that epileptic seizures were caused when a toxin, secreted from the Peyer's patches in the intestines, was discharged into the bloodstream. He recommended a fast lasting 18 to 25 days to allow this toxin to dissipate. Conklin probably treated hundreds of epilepsy patients with his "water diet" and boasted of a 90% cure rate in children, falling to 50% in adults. Later analysis of Conklin's case records showed 20% of his patients achieved freedom from seizures and 50% had some improvement.
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.
It’s important to remember that the goal of any dietary change is to promote a healthy lifestyle, so make sure to select a meal plan you can envision yourself following long term. If you know you will not be able to comply with such stringent carbohydrate restrictions for years to come, the ketogenic diet is most likely not the right choice for you.
Because the main tenet of the keto diet is counting and cutting carbs — a commonly used way to control blood sugar — this eating approach has become increasingly popular among people with type 2 diabetes who are looking to lower their A1C, which is the two- to three-month average measurement of blood sugar levels. Indeed, research suggests this diet may lead to fast weight loss and potentially lower blood sugar for people with the disease. (13)
Following a diet that drastically restricts carbohydrates requires carefully monitoring your food choices to ensure you are meeting your nutritional needs. Working together with a registered dietitian can make sure you follow this diet in a healthy manner without increasing your risk for complications or negative side effects. You can find a registered dietitian at EatRight.org.
One downside to a ketogenic diet for weight loss is the difficulty maintaining it. “Studies show that weight loss results from being on a low-carb diet for more than 12 months tend to be the same as being on a normal, healthy diet,” says Mattinson. While you may be eating more satiating fats (like peanut butter, regular butter, or avocado), you’re also way more limited in what’s allowed on the diet, which can make everyday situations, like eating dinner with family or going out with friends, far more difficult. Because people often find it tough to sustain, it’s easy to rely on it as a short-term diet rather than a long-term lifestyle.