Cut usable carbs to less than 30 g a day. Then eat fat and protein in a 1:1 ratio by grams. You can go in favor of fat in that ratio. Most people probably end up eating around 1 lb/gram of protein and fat. For instance a 200 pound man will eat 200g of fat and 200g of protein, each day in the prep phase. More if you are a big eater, less if you typically eat less.This is not a low calorie diet. Eat as much as you need. Don't overeat though, just eat enough so you aren't hungry.