JENNY CRAIG, founder of the eponymous weight-loss centers, is well known to many people from her appearances in ads for her company. She began working in the weight-management industry when she was trying to lose weight gained during pregnancy. She went on to work as a top executive for a chain of centers that was sold to NutriSystem, then, along with her husband Sid, relaunched Jenny Craig Systems in Australia--bringing it back to the United States in the mid-1980s. Today, Jenny Craig, Inc., is one of the largest weight-management companies in the world.