These findings are in line with another meta-analysis on 13 randomized controlled trials lasting at least six months comparing low-fat and low-carbohydrate diets. They noted that at six months, subjects who consumed less than 60 grams of carbohydrates per day had an average greater weight-loss of 8.8 lbs. compared to subjects on low-fat diets.  At one year, the difference had fallen to only 2.3 lbs. 
However, the researchers noted that it was still substantial and noted that “Evidence from this systematic review demonstrates that low-carbohydrate/high-protein diets are more effective at 6 months and are as effective, if not more, as low-fat diets in reducing weight and cardiovascular disease risk up to 1 year.”  They emphasized, however, that more research needs to be done to evaluate the long-term effects of the ketogenic diet on weight-loss.
Research supports the health benefits of a Mediterranean-style eating pattern that includes several different foods. It is the combination of these foods that appear protective against disease, as the benefit is not as strong when looking at single foods or nutrients included in the Mediterranean diet.  Therefore it is important to not simply add olive oil or nuts to one’s current diet but to adopt the plan in its entirety.
Gut health is extremely important for anyone looking to lose weight and increase overall health[*][*]. It is not uncommon for those who shift to a ketogenic diet to have a change in the production of bacteria in their colon (although not necessarily a bad thing – just a change)[*]. To help support this change and increase the healthy bacteria in your gut, try consuming more fermented foods such as sauerkraut, kimchi or kefir and/or supplement with a high-quality probiotic[*][*].
Milk is limited. There are no long-term risks to eating Mediterranean, says Cohen. But you may be put off if you’re big on eating a lot of milk and rely on it to get all the calcium you need. You’ll get to eat cheese and yogurt, but in smaller amounts. "To get enough calcium in the diet without milk, one would need to eat enough yogurt and cheese, or seek nondairy calcium sources," says Cohen. If needed, drink skim milk. Otherwise, nondairy calcium sources include fortified almond milk, sardines, kale, and tofu made with calcium sulfate. (30)
Consuming three tablespoons of EVOO isn’t enough to start shedding the kilos, Flynn says, explaining that the weight-loss effect kicks in when it’s combined with a healthy Mediterranean-style diet. This is rich in vegetables, fruit, legumes and whole grains, moderate in dairy and low in meat (about three serves of white meat or fish a week for women, and red meat only once or twice a month).