It’s been years since I’ve read much on this diet, but IIRC it’s not just eating a lot of high-fat foods and staying away from carbs; it’s a fairly strict diet that has to be followed very carefully. It can work amazingly well but it does require commitment.
We followed it strictly and weighed everything she ate on a gram scale. It's mega-Atkins. You are trying to create an abnormal metabolic state and then preserve it for a long time.