The president and CEO of the influential Robert Wood Johnson Foundation is stepping down "as soon as a successor is found," the Princeton-based foundation announced Tuesday.

Risa Lavizzo-Mourey, who trained in geriatrics at the University of Pennsylvania and has an MBA from the Wharton School,  has headed the $10 billion private foundation since January 2003.   The foundation focuses on health care and has in recent years promoted efforts to build a "Culture of Health."

The Korn Ferry executive search firm will be helping RWJF find a replacement.  Fred Mann, vice president of communications for the foundation,  said the search could take several months.

"I think the culture-of-health vision that we've had is something that we're committed to," he said.

That is a broad view of health that emphasizes prevention and healthy lifestyles as much as the delivery of medical care.

"Health is more than just going to the doctor or staying out of the hospital," he said.  "Health is reflected in everything we do."  That includes education, housing  and the criminal justice system.

Mann said Lavizzo-Mourey, 61,  pledged to stay a decade when she took the job.  It has now been almost 14 years.  "I think she just wanted to take some time off and figure out what her next act might be," he said.

Her departure was announced to the staff of about 270 Tuesday, he said.

According to the foundation, Lavizzo-Mourey has been named eight times to the Forbes list of the most powerful women in the world.  Under her leadership, the foundation announced in 2007 that it would devote $500 million to reducing childhood obesity.  It added an additional $500 million last year.  There are signs of progress, especially among the nation's youngest children.

According to her online biography,  Lavizzo-Mourey came to the foundation from Penn, where she was a professor of medicine and health-care systems.  She also directed Penn's Institute on Aging and was chief of geriatric medicine at the University of Pennsylvania's School of Medicine.