You say keto is a highly controversial topic. For those of us following a keto diet, there is no controversy whatsoever because the diet proves itself efficacious very quickly. I think the real controversy comes in because the ADA has been recommending dangerous levels of carbs for decades now, and they would lose face if they had to change their recommendation and admit they’ve been wrong for so long. You say there are not many studies on the keto diet, and I disagree with you. You’ll find the evidence if you look for it. Eric Westman, Steve Phinney, Jeff Volek and many other researchers have written volumes about this.
A 2012 study also showed that people on a low-carb diet burned 300 more calories a day – while resting! According to one of the Harvard professors behind the study this advantage “would equal the number of calories typically burned in an hour of moderate-intensity physical activity”. Imagine that: an entire bonus hour of exercise every day, without actually exercising. A later, even larger and more carefully conducted study confirmed the effect, with different groups of people on low-carb diets burning an average of between 200 and almost 500 extra calories per day.
At the first visit, participants were instructed how to follow the LCKD as individuals or in small groups, with an initial goal of ≤20 g carbohydrate per day. Participants were taught the specific types and amounts of foods they could eat, as well as foods to avoid. Initially, participants were allowed unlimited amounts of meats, poultry, fish, shellfish, and eggs; 2 cups of salad vegetables per day; 1 cup of low-carbohydrate vegetables per day; 4 ounces of hard cheese; and limited amounts of cream, avocado, olives, and lemon juice. Fats and oils were not restricted except that intake of trans fats was to be minimized. Participants were provided a 3-page handout and a handbook [11] detailing these recommendations. Participants prepared or bought all of their own meals and snacks following these guidelines.
To get the most benefit from the Keto diet, you should stay physically active. You might need to take it easier during the early ketosis period, especially if you feel fatigued or lightheaded. Walking, running, doing aerobics, weightlifting, training with kettlebells or whatever workout you prefer will boost your energy further. You can find books and online resources on how to adapt Keto meals or snacks for athletic training.
Although you'll be cutting way back on carbohydrates and sugar, some fruits are still okay to eat on the keto diet (though you'll still want to be mindful about quantity in order to remain in ketosis). The fruits that make the cut contain far fewer carbs than their off-limits cousins such as apples, pears, bananas, pineapples, papayas, grapes, and fruit juices in general.

Eating low-carb paleo means removing items like rice, pasta, and legumes from your diet completely, but the carbs you eat will be from vegetables like fruit, beets, sweet potatoes, and leafy greens, such as spinach and kale. The diet also cuts out processed food plus foods allowed on other low-carb diets, including milk and cheese, and some people have an easier time sticking with the diet when more carbs are included.

On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off. This is great if you’re trying to lose weight, but there are also other less obvious benefits, such as less hunger and a steady supply of energy. This may help keep you alert and focused.