I was on Medifast from May 15-June 30, 2012 -- about 6 weeks. In that time, I lost 15 lbs. I took July 1 - Aug. 18 "off" because I didn't want to be so strictly on plan during my overly social summer. I ate with lots of portion control when I was out with everyone, but on the days I wasn't being social, I followed Medifast. Luckily, I didn't gain any weight during my time "off plan," but that's because I exercised a lot and was careful not to overheat anything. Since I officially came back on plan on Aug. 19, I've lost another 2 lbs. Total weight loss: 17 lbs. Would love to lose 13 more!