A systematic review in 2016 found and analysed seven randomized controlled trials of ketogenic diet in children and young people with epilepsy. The trials were done among children and young people for whom drugs failed to control their seizures, and only one of the trials compared a group assigned to ketogenic diet with a group not assigned to one. The other trials compared types of diets or ways of introducing them to make them more tolerable. Nearly 40% of the children and young people had half or fewer seizures with the diet compared with the group not assigned to the diet. Only about 10% were still on the diet after a few years. Adverse effects such as hunger and loss of energy in that trial were common, with about 30% experiencing constipation.
If you are pregnant or are nursing, you should not follow a Ketogenic diet. You will not receive enough of the recommended carbohydrates, vitamins and nutrients necessary for yourself and your growing baby on this diet. Your obstetrician will recommend how many carbohydrates you should consume per meal and for snacks during each phase of your pregnancy. They will likely refer you to a Certified Diabetes Educator for nutritional counseling as well. Please check out The Diabetes Council’s FAQ’ About Gestational Diabetes for all your gestational diabetes related questions.
By restricting carbs to the degree that the keto diet recommends, you will stimulate the production of ketones and eventually enter nutritional ketosis. As a result, you will start burning more ketones for fuel. Ketones have also been found to help increase weight loss, lower glucose and insulin levels, decrease insulin resistance, and improve energy efficiency.  
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.
Cons: That same study on the perks of being a keto athlete also found those same dieters had a lower exercise economy (how efficiently you use oxygen while moving). And whereas pretty much every other diet offers flexibility in the macro range, eating a few too many grams of carbs or protein will knock your body out of ketosis, so you have to be pretty committed to see the perks of this one. Lastly, the low protein count required to stay in ketosis may be holding you back here: A study analysis in Nutrition, Metabolism, and Cardiovascular Diseases found upping protein on a keto diet by just 5% tripled fat loss.
One thing you’ll find people love about the Mediterranean diet is the allowance of moderate amounts of red wine. “Moderate” means 5 ounces (oz) or less each day for women (one glass) and no more than 10 oz daily for men (two glasses). (1) Above all else, these meals are eaten in the company of friends and family; strong social ties are a cornerstone of healthful lives — and a healthful diet. Here, food is celebrated.
In terms of weight loss, you may be interested in trying the ketogenic diet because you’ve heard that it can make a big impact right away. And that’s true. “Ketogenic diets will cause you to lose weight within the first week,” says Mattinson. She explains that your body will first use up all of its glycogen stores (the storage form of carbohydrate). With depleted glycogen, you’ll drop water weight. While it can be motivating to see the number on the scale go down (often dramatically), do keep in mind that most of this is water loss initially.
The DASH (Dietary Approaches to Stop Hypertension) diet is sometimes prescribed by doctors to help treat high blood pressure. Blood pressure is the amount of pressure that blood places against the walls of arteries. It will normally vary throughout the day but if it remains too high, this is called high blood pressure or hypertension. Untreated high blood pressure can lead to heart disease, stroke, congestive heart failure, kidney disease, and blindness. 
Dairy products contain varying amounts of lactose (milk sugar), which slows down weight loss. What’s more, part of the protein in milk generates a significant insulin response, which can have the same effect. Consequently, cutting back on dairy products may accelerate weight loss. This applies especially to dairy products typically lacking in fat, such as regular milk and various yogurts, but be careful with full-fat dairy such as cream and cheese all the same. And don’t forget whey protein powder, which is pure milk protein.
Recent studies have also shown that garlic supports blood-sugar metabolism, and helps control lipid levels in the blood. What’s more? Eating garlic can help boost your immune system, help ward off heart disease, fight inflammation, increase memory retention, and lower blood pressure, so consider adding some to your next meal. At the very least, it is preferable over salt, which can lead to water weight gain and bloating.
At first glance the ketogenic (keto) diet may seem like a crazy idea for type 2 diabetics. After all, many patients are put on diets to help them lose weight. The keto diet is high in fat, but it is very low in carbs, and this combination can help change the way your body stores and uses energy. With this diet your body converts fat instead of sugar into energy, which can improve blood glucose levels while reducing the need for insulin.
"The keto diet is primarily used to help reduce the frequency of epileptic seizures in children. While it also has been tried for weight loss, only short-term results have been studied, and the results have been mixed. We don't know if it works in the long term, nor whether it's safe," warns registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital.
A study with an intent-to-treat prospective design was published in 1998 by a team from the Johns Hopkins Hospital and followed-up by a report published in 2001. As with most studies of the ketogenic diet, there was no control group (patients who did not receive the treatment). The study enrolled 150 children. After three months, 83% of them were still on the diet, 26% had experienced a good reduction in seizures, 31% had had an excellent reduction and 3% were seizure-free.[Note 7] At twelve months, 55% were still on the diet, 23% had a good response, 20% had an excellent response and 7% were seizure-free. Those who had discontinued the diet by this stage did so because it was ineffective, too restrictive or due to illness, and most of those who remained were benefiting from it. The percentage of those still on the diet at two, three and four years was 39%, 20% and 12% respectively. During this period the most common reason for discontinuing the diet was because the children had become seizure-free or significantly better. At four years, 16% of the original 150 children had a good reduction in seizure frequency, 14% had an excellent reduction and 13% were seizure-free, though these figures include many who were no longer on the diet. Those remaining on the diet after this duration were typically not seizure-free but had had an excellent response.
What the expert says: ‘This is something that is used for athletes as part of their training. While it can lead to weight loss, carbohydrates are an energy source for the body, and restricting them can lead to headaches, fatigue and difficulty concentrating. You would be better to find the level of carbohydrates your body needs by eating normal portion sizes and a balance of all food groups.’
“A lot of people think the foundation of a paleo diet is high-fat meat, but I suggest that it’s vegetables,” says Hultin. The concept is to eat only foods — including meat, fish, poultry, eggs, fruits, and vegetables — that would have been available to our Paleolithic ancestors. This means grains, dairy, legumes, added sugar, and salt are all no-no’s.
That’s because the DASH Diet has been proven to work, says Reshmi Srinath, M.D., an assistant professor at the Icahn School of Medicine at Mount Sinai. One study found that people who followed the DASH Diet had lower blood pressure and LDL (bad) cholesterol levels than those who consumed a typical American diet or an American diet infused with extra fruits and veggies.
Eating out is possible on the DASH Diet, but proceed with caution. Restaurant meals are notoriously salty, oversized and fatty, so you’ll need to be conscientious if you dine out. NHLBI suggests avoiding salt by shunning pickled, cured or smoked items; limiting condiments; choosing fruits or vegetables instead of soup; and requesting the chef find other ways to season your meal. You can also drink alcohol moderately on the DASH Diet.
3. Diabetes prevention. In a new Annals of Internal Medicine study, 215 type 2 diabetics were asked to follow either a low-fat or a Mediterranean diet. After four years only 44 percent of the Mediterranean group needed diabetes medication -- but 70 percent of the low-fat eaters did. The Med dieters also lost more weight. Other research shows that the diet helps people with pre-diabetes lower their blood sugar enough to avoid developing full-blown type 2 diabetes.
A 2010 study in Diabetes, Obesity and Metabolism assigned 259 overweight diabetics to one of three diets: a low-carb Mediterranean diet, a traditional Mediterranean diet or a diet based on recommendations from the American Diabetes Association. All groups were told to exercise 30 to 45 minutes at least three times per week. After a year, all groups lost weight; the traditional group lost an average of about 16 pounds while the ADA group dropped 17 pounds and the low-carb group lost 22 pounds.
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.