Maybe mine is a dud. There is no way I lost 7 pounds of muscle - not only am I almost 2 sizes smaller, I lift weights and can see a visible difference in my muscles, esp. upper body. Plus, in checking my bf through measurements when I started, and again a few weeks ago, it showed a 6% drop in bf. That's why I assume that there is prob. a malfunction. It doesn't work for my husband, either, who has lost about 15 pounds. For him it only showed a 1% drop in bf. Since his belly is now relatively flat, I doubt he lost muscle, also...