New Jersey Gov. Chris Christie, using an alias, checked into a hospital in February, had lap-band surgery on his stomach and has already lost 40 pounds, according to a newspaper report.

The New York Post, in an exclusive story, said Christie told them he had the surgery for his family's sake – and not as preparation as a run for president. Turning 50 last year prompted the move, he said, adding that he wanted to be around for his four children.

"I've struggled with this issue for 20 years," Christie told the publication. "For me, this is about turning 50 and looking at my children and wanting to be there for them."

The Republican governor underwent what's known as laparoscopic adjustable gastric banding – a surgery that shrinks the stomach, forcing patients to eat less. In such surgeries, an adjustable band is tightened around the upper portion of the stomach.

Christie said he recently went to a steakhouse, but could only get about a third of a way through a steak.