Fast weight loss must be achieved in a healthy way. If fast weight loss occurrs, it can result in loss of muscle mass. This is not healthy and will result in increased body fat. To achieve fast weight loss, and maintain muscle mass, protein and nutrition is required in the correct amounts. Avoid starvation, which will lose muscle mass and ensure enough protein and nutrition by using Herbalife nutritional protein shakes. Body fat can't be lost if you have too little muscle mass. Fast weight loss, while enjoying energy and healthy muscle mass, must be done with the right protein and nutrition. Otherwise, the fast weight loss, will be fast fat gain. so, in summary, fast weight loss, must be healthy weight loss, maintaining muscle mass and reducing body fat, in order to be successful. Good luck with your fast, healthy weight loss