A Losing Personality; January / February 2011; Scientific American Mind; by Winnie Yu; 4 Page(s)

Losing weight has never been an easy endeavor, as anyone who has ever tried knows. Among the challenges: changing ingrained habits that led to the weight gain. Everyone attributes his or her success to different strategies and programs, be it Weight Watchers, gastric bypass surgery or sheer willpower, but all tend to agree that eating less and moving more are at the heart of any successful effort.

But what makes one person able to put that simple formula into action, whereas another fails in the attempt? Only about one fifth of people who lose at least 10 percent of their weight keep it off for at least a year, according to a 2005 study in the American Journal of Clinical Nutrition. Of course, numerous biological factors play a role in weight loss, including the size of your body, its muscle and fat content, and your metabolic rate. In recent years psychologists have begun looking at personality traits as critical variables in the dieting equation.