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 there is 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. Almost 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. There is some evidence that adults with epilepsy may benefit from the diet, and that a less strict regimen, such as a modified Atkins diet, is similarly effective. The most common adverse effect is constipation, affecting about 30% of patients—this was due to fluid restriction, which was once a feature of the diet, but this led to increased risk of kidney stones and is no longer considered beneficial.
Finally, the ketogenic diet has been shown to be an effective adjuvant for the treatment of certain cancers. The beneficial effects have been demonstrated for various cancer types, including prostate, colon, and brain cancer, such as glioblastoma. Its efficacy has been documented in animal models as well as in humans, including in pediatric patients.
I read in the news that the DASH diet was supposed to be THE top-rated diet by experts, so I took a closer look with this book. I was disturbed instead by recommendations of processed low fat cheeses, low fat yoplait yogurt (so much sugar and un-pronounceable ingredients I don't even understand why this was suggested), and sugar-free Jello. I prefer a whole-foods, plant-based, low processed approach - so this diet definitely isn't for me. I think I'll keep looking.
Prior to the advent of exogenous insulin for the treatment of diabetes mellitus in the 1920's, the mainstay of therapy was dietary modification. Diet recommendations in that era were aimed at controlling glycemia (actually, glycosuria) and were dramatically different from current low-fat, high-carbohydrate dietary recommendations for patients with diabetes [1,2]. For example, the Dr. Elliot Joslin Diabetic Diet in 1923 consisted of "meats, poultry, game, fish, clear soups, gelatin, eggs, butter, olive oil, coffee, tea" and contained approximately 5% of energy from carbohydrates, 20% from protein, and 75% from fat . A similar diet was advocated by Dr. Frederick Allen of the same era .
But beyond that, experts aren't convinced that the keto diet has any other scientifically-proven health benefits. In fact, it may have some distinct downsides. If you follow the keto diet incorrectly, for example (like by eating lots of saturated fats, versus healthy unsaturated fats), you're at risk of raising your cholesterol levels. “The best strategy to keep your heart healthy is to get as much fat as possible from unsaturated sources such as olive, avocado and canola oils, nuts, seeds, avocados, and olives," says Ansel.
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.
The ketogenic diet reduces seizure frequency by more than 50% in half of the patients who try it and by more than 90% in a third of patients. Three-quarters of children who respond do so within two weeks, though experts recommend a trial of at least three months before assuming it has been ineffective. Children with refractory epilepsy are more likely to benefit from the ketogenic diet than from trying another anticonvulsant drug. There is some evidence that adolescents and adults may also benefit from the diet.
Recently, four studies have re-examined the effect of carbohydrate restriction on type 2 diabetes. One outpatient study enrolled 54 participants with type 2 diabetes (out of 132 total participants) and found that hemoglobin A1c improved to a greater degree over one year with a low-carbohydrate diet compared with a low-fat, calorie-restricted diet [5,6]. Another study enrolled 8 men with type 2 diabetes in a 5-week crossover outpatient feeding study that tested similar diets . The participants had greater improvement in glycohemoglobin while on the low-carbohydrate diet than when on a eucaloric low-fat diet. The third study was an inpatient feeding study in 10 participants with type 2 diabetes . After only 14 days, hemoglobin A1c improved from 7.3% to 6.8%. In the fourth study, 16 participants with type 2 diabetes who followed a 20% carbohydrate diet had improvement of hemoglobin A1c from 8.0% to 6.6% over 24 weeks . Only these latter three studies targeted glycemic control as a goal, and two of these were intensely-monitored efficacy studies in which all food was provided to participants for the duration of the study [7,8]. Three of the studies [6,8,9] mentioned that diabetic medications were adjusted but only one of them provided detailed information regarding these adjustments . This information is critical for patients on medication for diabetes who initiate a low-carbohydrate diet because of the potential for adverse effects resulting from hypoglycemia.
Both groups experienced no notable adverse effects in their health. In the 29 subjects who successfully completed the calorie-restricted diet, researchers observed an average 16% reduction in fasting glucose, 2.7 reduction in BMI, and loss of 6.9 kg of bodyweight.  However, in the 21 subjects that successfully completed the very-low carbohydrate ketogenic diet, subjects experienced an average 19.9% reduction in fasting glucose, 3.9 decrease in BMI, and loss of 11.1 kg of bodyweight. 
“During physiological ketosis ketonemia reaches maximum levels of 7/8 mmol/L with no change in pH while in uncontrolled diabetic ketoacidosis it can exceed 20 mmol/L with a concomitant lowering of blood pH. Blood levels of ketone bodies in healthy people do not exceed 8 mmol/L precisely because the central nervous system (CNS) efficiently uses these molecules for energy in place of glucose,” researchers summarize.
A 2012 CDC study found that the average adult consumes about 100 calories worth of alcohol daily, but favoring a glass of wine instead of beer or sugary cocktails can drastically reduce that figure and make your waistline slimmer. In addition to having fewer calories than most alcoholic beverages, red wine, in particular, is a good source of those waist-shrinking flavonoids that are also found in red fruits. Resveratrol, a particular flavonoid found in red wine, is believed to have heart health benefits because it helps prevent blood vessel damage and reduces your ‘bad cholesterol.’ Just remember to imbibe in moderation.
While it’s true that low-carb diets do raise the so-called bad LDL-cholesterol in some people, it’s important to note that LDL-C, when influenced by diet, has never been shown to have any effect on cardiovascular risk. Large clinical trials and observational studies show that one’s level of LDL-C and the lowering of LDL-C through diet is not reliably linked to cardiovascular outcomes.21, 22, 23
Con: Results can vary depending on how much fluid you drink. By drinking more water, you dilute the concentration of ketones in the urine and thus a lower level of ketones will be detected on the strips. The strips don’t show a precise ketone level. Finally, and most importantly, as you become increasingly keto-adapted and your body reabsorbs ketones from the urine, urine strips may become unreliable, even if you’re in ketosis.