Gov. Chris Christie, who has both joked about his weight and said that it’s a real concern, secretly underwent a weight-loss surgery in February that experts say could help him if he gets exercise and watches what he eats.

He said Tuesday that he decided to have a band placed around his stomach to restrict how much food he can eat for his long-term health and for his family, not to lay the groundwork for running for president in 2016.

“This is a hell of a lot more important to me than running for president,” Christie, a father of four, said at a news conference in Newark. “This is about my family’s future.”

Christie, who appears thinner than he did earlier this year, said he decided to have the surgery around the time he turned 50 in September and initially planned to have it done in November. But Superstorm Sandy’s destruction in New Jersey pushed back the procedure until February, after the governor’s weight made news multiple times.

He said he suggested the idea and his family supported it.

Two of Christie’s children are still in elementary school.

“I’m in this father business for a while,” he said. “And I hope one day dear God to be in grandfather business.”

He told only a few top staffers — not his communications office or campaign staff. He said his communications director was caught by surprise on Monday when a New York Post reporter asked directly if he’d had the procedure. The spokeswoman, he said, did not know. The Post first reported the surgery Tuesday.

Christie said he never intended to make a public announcement and that he’s “not going to be the guy who writes a book” about losing weight.