The correct answer is gallbladder
Weight Cycling...Facts About "Yo-Yo<span>" </span>Dieting<span>. Weight cycling is the repeated loss and regain of body weight. When weight cycling is </span>the result<span> of </span>dieting, it is often called "yo-yo<span>" </span>dieting<span>.
cited from-</span>http://www.medicinenet.com/script/main/art.asp?articlekey=21745
This look like something I can handle
