Having too much protein: This is likely not an issue for most people, but for others having too much protein can negatively impact ketosis, due to its glucogenic effects. The level needed to achieve this is still unknown, but likely higher than we originally thought. To prevent this, try to eat whole foods as much as possible instead of isolated protein sources (i.e., straight protein shakes).
Variations on the Johns Hopkins protocol are common. The initiation can be performed using outpatient clinics rather than requiring a stay in hospital. Often, no initial fast is used (fasting increases the risk of acidosis, hypoglycaemia, and weight loss). Rather than increasing meal sizes over the three-day initiation, some institutions maintain meal size, but alter the ketogenic ratio from 2:1 to 4:1.[9]
This article was reviewed by Jes Harvey, RD, on November 7, 2019. Harvey is a registered dietitian specializing in the ketogenic diet for children and adults. She is a certified specialist in Pediatric Nutrition and educates children with epilepsy on the ketogenic diet as an anti-seizure medication. Harvey also manages a private nutrition practice consulting adults on the ketogenic way of eating.
On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off. This is great if you’re trying to lose weight, but there can also be other, less obvious benefits, such as less hunger and a steady supply of energy (without the sugar peaks and valleys we can get from high carb meals). This may help keep you alert and focused.

When your body burns its stores of fat, it can be hard on your kidneys. And starting a ketogenic diet -- or going back to a normal diet afterward -- can be tricky if you’re obese because of other health issues you’re likely to have, like diabetes, a heart condition, or high blood pressure. If you have any of these conditions, make diet changes slowly and only with the guidance of your doctor.
Those issues can be part of what's known as the “keto flu,” Warren says. Other side effects of the keto diet, all of which are tied to carb withdrawal, can include lightheadedness, nausea, mental fog, cramps, and headaches, in addition to tiredness. Luckily, the keto flu doesn't usually last more than a week—which is coincidentally about when people start to see the number on the scale go down, says Warren.
If you “slip up” on a ketogenic diet, it is not the end-of-the-world nor does it mean you should continue to be off the wagon. Unfortunately, having frequent “slip-ups” or “cheat days” may prevent you from becoming “keto-adapted.” However, an occasional “slip-up” for someone who is already “keto-adapted” may not be as detrimental. Get back on track and get back in your routine. Find support groups and alternative recipes to avoid these pitfalls and setbacks.
When something is popular, it’s pretty much a guarantee that people are going to come up with new or easier ways of doing it. Enter the lazy keto and dirty keto diets. With lazy keto, people try to limit their carb intake to 20 to 50 grams a day but don’t really track it; with dirty keto, people generally follow the same macronutrient breakdown as "regular" keto, but it doesn't matter where those macronutrients come from. 

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.

Ketogenesis has existed as long as humans have. If you eat a very low amount of carbohydrates, you starve your brain of glucose, its main fuel source. Your body still needs fuel to function, so it taps into your reserve of ketones, which are compounds the liver creates from fat when blood insulin is low. This process is known as ketosis: It’s like when a hybrid car runs out of gas and reverts to pure electricity.

Achieving optimal ketosis hinges on finding the right balance of macronutrients (or “macros” in keto-speak); these are the elements in your diet that account for the majority of your calories, a.k.a. energy—namely, fat, protein, and carbohydrates. By the way, it’s often “net grams” of carbohydrates that are counted toward your daily intake; “net” deducts the amount of fiber in a food from its carbohydrate total.
There are many ways in which epilepsy occurs. Examples of pathological physiology include: unusual excitatory connections within the neuronal network of the brain; abnormal neuron structure leading to altered current flow; decreased inhibitory neurotransmitter synthesis; ineffective receptors for inhibitory neurotransmitters; insufficient breakdown of excitatory neurotransmitters leading to excess; immature synapse development; and impaired function of ionic channels.[7]