H Tann! My boyfriend lost a total of 29 pounds with the Optifast liquid protien diet. He stuck to it and when he got hungry, he filled up on water. He was very committed to this diet and it paid off. He also committed to the strict diet postop. Paulm235, you can stay on the Optifast diet as long as you want, but one month costs over $600.00, plus everytime he went on a liquid diet, or any diet, the weight came off, but as soon as he stopped the diet, the weight came back on double. The diet is to "lighten" the liver and put your body in a state of ketosis prior to surgery so the recovery time is shortened and the pain is less, not to mention the surgical procedure is cut down so you aren't under the general anesthesia for too long. If he had not committed to this preop diet, he would have been in surgery for two or more hours. He was banded in Troy Michigan by Dr. Zoe Deol M. D. Good luck to all of you!!