It's a diet that induces ketosis. Such diets are high in protiens, low in carbs and have varying amounts of fat depending on the specific diet. Atkins is one. Ketones are the product of partially metabolized fat that is excreted through the kidneys, you pee it out. Since your carb intake is low your brain which generally relies on carbs for nourishment it switches to protiens and fats as substitutes. I have lost a ton of weight (literally) using these diets. I have never sustained the loss.
I have a couple of nutrition specialists, including an MD, in my life. Neither recommends these diets. Slow and sustained weight loss is what they preach. If you're interested, I can give you details.
