Insulin is released in the blood and used to control blood sugar levels including signaling the liver to stop producing sugar. If this system is impaired and the body does not use insulin properly, which is called insulin resistance, individuals are likely to develop high blood sugar levels. In this study the researchers showed that for ketogenic diets this process for controlling blood sugar levels does not work properly and there was insulin resistance in the liver. When the liver is unable to respond to normal levels of insulin to control blood sugar levels this may lead to an increased risk of Type 2 diabetes.
Hello Marylin, Yes, the Mediterranean diet has been shown to be effective for weight loss. However, you dip need to consume the right amounts of food (calories) to lose weight as that varies depending on age, gender activity level etc. Here is a link to the Greek Nutrition Guidelines that includes servings https://www.olivetomato.com/eat-like-greek-greek-dietary-guidelines-a-better-choice/
The types of foods listed are not comprehensive. For example, avocados are not included so it is not clear if they would be categorized as a fruit or a fat serving. Certain foods are placed into questionable categories: pretzels are placed in the grain group even though they have fairly low nutrient content and no fiber; frozen yogurt is placed in the dairy group even though most brands contain little calcium and vitamin D and are high in added sugar. The general term “cereals” are placed in the grain group but different types of cereals can be highly variable in nutrient and sugar content.
The ketogenic diet seems straightforward. Unlike a typical low-calorie diet, however, a high-fat diet requires careful monitoring. In fact, you may start the diet in a hospital. Your doctor needs to monitor both blood glucose and ketone levels to make sure that the diet isn’t causing any adverse effects. Once your body adjusts to the diet, you may still need to see your doctor once or twice a month for testing and medication adjustments.
Pros: Technically a subtype of low-carb diet, the keto diet is unique: By depriving your body of carbohydrates, you not only force your body to become fat-adapted, but also, if you keep protein low as well, elevate your levels of ketone bodies, which is basically a sign your body is running on fat. The keto diet puts you in a unique metabolic state called ketosis wherein your brain burns ketones instead of glucose—and, in doing so, supposedly leads to clearer thinking. Physically, eating such a high amount of fat significantly increases your body’s ability to burn body fat, according to the study analysis. Research also shows keto athletes have a higher VO2 max, and are able to lose fat without losing strength or power.
The first meta-analysis worth noting collected the data from 10 randomized trials comprising 1376 participants in total.  After analyzing the research, a key relationship emerged between dietary carbs and blood sugar levels. In short, the researchers described their finding thus: “the greater the carbohydrate restriction, the greater glucose lowering…” 
Thank you for this comment. It is truth! I keep telling people about this diet. It is literally the best diet I have ever been on. I can eat good food, I feel full, my weight is dropping, I feel better and I can actually feel the difference. While it is great for a professional to be skeptical of emerging diet trends (and lets face it, most diet trends are garbage peddled by snake oil salesmen), this one actually has science from some prestigious institutions behind it, not a marketing scheme.
The benefits above are the most common ones. But there are others that are potentially even more surprising and – at least for some people – life changing. Did you know that a keto diet can help treat high blood pressure, may result in less acne, may help control migraine, might help with certain mental health issues and could have a few other potential benefits?