IP is a high protein, low carb low fat diet. You essentially are putting your body into a state of ketosis in order to build lean muscle mass and burn fat. I've been on it since October and have last @ 50 lbs. I had to take a few weeks of for financial reasons or I'm sure that # would be higher. My mom list 85 in about 6 months and has maintained the loss for 4 months so far.