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 fuelling brain-function.
If there is very little carbohydrate 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.
The original therapeutic diet for paediatric epilepsy provides just enough protein for body growth and repair, and sufficient calories to maintain the correct weight for age and height. This classic ketogenic diet contains a 4:1 ratio by weight of fat to combined protein and carbohydrate. This is achieved by excluding high-carbohydrate foods such as starchy fruits and vegetables, bread, pasta, grains and sugar, while increasing the consumption of foods high in fat such as nuts, cream and butter.
Most dietary fat is made of molecules called long-chain triglycerides (LCTs). However, medium-chain triglycerides (MCTs) — made from fatty acids with shorter carbon chains than LCTs—are more ketogenic. A variant of the classic diet known as the MCT ketogenic diet uses a form of coconut oil, which is rich in MCTs, to provide around half the calories. As less overall fat is needed in this variant of the diet, a greater proportion of carbohydrate and protein can be consumed, allowing a greater variety of food choices.
Weight Loss Diets
The Atkins Diet, was potentially a ketogenic diet. I'm not sure how much Dr Atkins understood that.
The New Atkins Diet is certainly firmly based in science and is ketogenic, although they don't say much about that in their publicity.
Paleo diets, might or might not be ketogenic, depending on the knowledge of the participants.
The Banting Diet, is promoted by The Real Meal Revolution, and is also heavily based on the latest science. The Banting Diet makes achieving ketosis a prime objective. A sensible first step is to change what you eat for breakfast.
Defensive Dietary Strategy
It's now commonly understood, that spending some time in ketosis might be helpful in reducing the viability of pre-cancers, so that the immune system might identify them and eliminate them.
If Alzheimer's disease or dementia, concern you, living in ketosis might provide a preventative strategy.
There are also suggestions that ketosis is helpful in several other medical conditions. Since it's a relatively inexpensive and very safe intervention, the downside of an experiment in living a Banting Lifestyle, is worth a try, if you have health concerns. There is a long list on medical problems where this might be applicable advice.