Medifast claims to be a low-fat, low-carb, ultra-low-calorie diet plan that allows the typical dieter to remain healthy while losing weight at a rate substantially faster than one would lose under a traditional diet plan. Medifast's claims in this regard are based on their claim that, when followed properly, the Medifast diet plan induces the body into a mild state of ketosis, whereby fat is burned instead of muscle. There is no cost to join any official Medifast program: the only thing Medifast charges for is its food.