A systematic review in 2018 looked at 16 studies on the ketogenic diet in adults. It concluded that the treatment was becoming more popular for that group of patients, that the efficacy in adults was similar to children, the side effects relatively mild. However, many patients gave up with the diet, for various reasons, and the quality of evidence inferior to studies on children. Health issues include high levels of low-density lipoprotein, high total cholesterol, and weight loss.[24]

Nina, this is a brilliant article, thank you. I have shared it with my Low Carb & Keto Facebook US & UK groups, many of whom are new to this way of eating for weight loss, reversing Diabetes, preventing Diabetes and improving their health. My members receive regular low carb recipes and support but articles like this, really do reinforce their reasons for staying low carb and helps them justify their lifestyle to family, friends and some Medics!

Increases in cholesterol levels need discussion too. We do see temporary increases in cholesterol levels often as individuals transition onto a ketogenic diet. However, when you examine lipid particle size (a more important way to look at the cardiovascular risks), the risk pattern doesn’t seem to increase with a ketogenic diet. Harvard Health has written about lipid particle size here before: http://www.health.harvard.edu/womens-health/should-you-seek-advanced-cholesterol-testing-
^ Ketogenic "eggnog" is used during induction and is a drink with the required ketogenic ratio. For example, a 4:1 ratio eggnog would contain 60 g of 36% heavy whipping cream, 25 g pasteurised raw egg, saccharin and vanilla flavour. This contains 245 kcal (1,025 kJ), 4 g protein, 2 g carbohydrate and 24 g fat (24:6 = 4:1).[17] The eggnog may also be cooked to make a custard, or frozen to make ice cream.[37]
Anticonvulsants suppress epileptic seizures, but they neither cure nor prevent the development of seizure susceptibility. The development of epilepsy (epileptogenesis) is a process that is poorly understood. A few anticonvulsants (valproate, levetiracetam and benzodiazepines) have shown antiepileptogenic properties in animal models of epileptogenesis. However, no anticonvulsant has ever achieved this in a clinical trial in humans. The ketogenic diet has been found to have antiepileptogenic properties in rats.[56]
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]
If you’re wondering about the difference between ketosis and diabetic ketoacidosis, you’re not alone. “The word ketone is scary for most people with type 1 diabetes because they relate ketones to diabetic ketoacidosis,” says Patti Urbanski, MEd, RD, CDE, a certified diabetes educator with St. Luke’s Hospital in Duluth, Minnesota. “But with the ketogenic diet, we’re talking about a much lower level of ketones.”
People claiming huge benefits of these supplements – despite the lack of solid scientific support – may sometimes have a financial reason to believe in the supplements. Some of these products are sold under a multi-level marketing arrangement, where sales people are paid based on commission. For example, the company Prüvit sells drinkable ketones, called KETO//OS with a multi-level marketing structure.