Emerging evidence suggests that eating this way may offer protective effects for those with and at risk for type 2 diabetes. For one, Mediterranean eating improves blood sugar control in those already diagnosed with the condition, suggesting it can be a good way to manage the disease. What’s more, given those with diabetes are at increased odds for cardiovascular disease, adopting this diet can help improve their heart health, according to a paper published in April 2014 in the journal Nutrients. (4)
Weight loss caused by low-carb diets isn’t just because of a loss of “water weight”. In research studies that measured change in body fat, subjects eating low-carb diets had a greater loss in body fat than those eating low-fat diets. Additionally, keto diets lead to a greater reduction in waist circumference, a critical indicator of harmful stomach fat.
Interestingly, a few years ago the American Heart Association lowered the recommended intake of saturated fat to no more than 7% of total calories eaten each day. Olive oil is 14% saturated fat. (The average American consumes a diet with about 14% saturated fat.) So if you’re using a lot of olive oil on your food, it’d be hard to have a diet that’s less than 14% saturated fat, which means your arteries are being subjected to double the saturated-fat-limit that the AHA recommends.
A diet high in fresh plant foods and healthy fats seems to be the winning combination for longevity. Monounsaturated fat, the type found in olive oil and some nuts, is the main fat source in the Mediterranean diet. Over and over, studies show that monounsaturated fat is associated with lower levels of heart disease, cancer, depression, cognitive decline and Alzheimer’s disease, inflammatory diseases and more. These are currently the leading causes of death in developed nations — especially heart disease.
This meta-analysis also provides us with an explanation for why keto and low-carb diets have not always been found to confer better weight loss than low-fat diets. When protein and calories are controlled, changes in weight loss results remain relatively equal. This not only supports the theory that calorie deficits are the key to weight loss, but it also provides evidence against the hypothesis that carbs and insulin are the cause of obesity. 
Evidence suggests that the Mediterranean diet serves as an anti-inflammatory dietary pattern, which could help fight diseases related to chronic inflammation, including metabolic syndrome and type 2 diabetes. (9) One reason the Mediterranean diet might be so beneficial for preventing diabetes is because it controls excess insulin, a hormone that controls blood sugar levels, makes us gain weight and keeps the weight packed on despite us dieting.
What is the key to a healthy diet?According to the Harvard Medical School Food Pyramid, the total amount of fat you eat, whether high or low, is not really linked with disease. What really matters is the type of fat you eat. The "bad" fats -- saturated and trans fats -- increase the risk for certain diseases. The "good" fats – mono-unsaturated and poly-unsaturated fats –- like those contained in olive oil lower disease risk. The key to a healthy diet is to substitute good fats for bad fats, and to avoid trans fats.
Keto meals seemed so heavy and rich to me, and it just wasn't how I was used to eating. Plus, I consider myself a flexitarian, so the thought of eating more meat-and more often than I typically would-gave me pause. Dr. Axe assured me that even vegetarians could pull off a keto diet if they planned well enough. (Vegans can, too.) That said, he's a proponent of animal products and red meat specifically, because of the iron it provides for women (who are more susceptible to deficiency) and because it can bolster energy when carbs are lacking. (These Are the Other Things Vegetarians Need to Be Aware of Before Going Keto.)
The first group of 75 consumed a low-carbohydrate diet with less than 40 grams of carbohydrates per day. The second group of 73 consumed a low-fat diet with less than 30% of calories from fat and less than 7% of calories from saturated fat. Both groups regularly received nutritional counseling periodically throughout the study meeting with each participant meeting with a dietitian for a total of 10 sessions