By Liza Hamm
February 22, 2010 12:00 PM

Carnie Wilson is not alone when it comes to putting on pounds after weight-loss surgery. “At least 15 percent of people—one in seven—gain all their weight back after gastric bypass,” says Dr. Mehmet Oz, who confronted Wilson on his Feb. 4 show. “Gastric does not take care of the psychological issues. She needs to break her addiction to food.” He is optimistic for her: “People change based on what they feel, not what they know, and she fears passing her addiction on to her daughters. That will motivate more than looking good for a magazine.”