By Leslie Larson

PUBLISHED: 08:01 EST, 7 May 2013 | UPDATED: 08:37 EST, 7 May 2013

New Jersey Gov. Chris Christie has revealed that he underwent lap-band surgery to lose weight.

Gov. Christie had the surgery on President's Day, February 16, checking into the hospital under a false name, and sources estimate he has already lost 40 lbs.

The outspoken Republican told the New York Post he resolved to have the operation after he celebrated his 50th birthday last September and decided he needed to get serious about his health.

Christie, dubbed the savior of the Republican Party, told the Post that after celebrating his milestone birthday he realized he needed to take action for the sake of his wife, Mary Pat, and four children.

'I’ve struggled with this issue for 20 years,' he said about his weight, a much discussed topic during his political career.

'For me, this is about turning 50 and looking at my children and wanting to be there for them,' the politician, who is currently running for a second terms as the Garden State governor, said.

'I know it sounds crazy to say that running for president is minor, but in the grand scheme of things, it was looking at Mary Pat and the kids and going, "I have to do this for them, even if I don’t give a crap about myself,"' he continued, downplaying a political motivation for the procedure.

Though the GOP darling insisted his decision was not politically motivated, skeptics suggested the surgery was an important step to show voters that he is serious about a presidential bid in 2016.

Christie received massive support from party faithfuls across the country before the 2012 presidential election, urging him to throw his hat in the ring.

Instead, Christie was a key surrogate for Republican Presidential candidate Gov. Mitt Romney, until Hurricane Sandy when Christie was criticized for being too supportive of  President Obama's response to the crisis that left the Garden State badly damaged.

More than one week before he had the operation, Gov. Christie appeared on CBS' Late Show with Dave Letterman on February 4 when the politician joked about all those making fun of his size.

He even pulled out a donut and noshed on the pastry on-air, saying that his weight was 'fair game' for comedic fodder.

White House physician, Dr Connie Mariano, spoke out about Christie's health, after his appearance on Letterman, saying that voters should be concerned that Christie would die in office if he was elected president.

In his trademark no holds barred style, Christie told the doctor to 'shut up.'

'This is just another hack who wants five minutes on TV,' he said about Dr Mariano.

Christie said he had the surgery on 7am, on February 16, and the operation lasted 40 minutes. The politician was home that same afternoon.

The politician has never disclosed his actual weight but it has been suggested that it teetered from 300 to 350 lbs.

Sources estimate he has already lost nearly 40lbs in the three months since the operation.

'A week or two ago, I went to a steakhouse and ordered a steak and ate about a third of it and I was full,' he said.

He has suggested in the past that the operation was too drastic a measure for him to consider but the New Jersey native sought guidance from his close friend, New Jersey Jets coach Rex Ryan, about the decision.

Ryan, 50, underwent the operation in 2010 and has lost 100 pounds.

Christie went to Ryan's doctor Dr George Fielding, head of NYU Medical Center’s Weight Management Program.

In order to ensure secrecy, Dr Fielding consulted with Christie at the governor's home in Mendham, NJ so Christie was never seen at the physician's office.