Memo to Chris Christie: You've got a new contract with life -- under some pretty favorable terms.

The New Jersey governor and possible 2016 Republican presidential contender quietly underwent lap-band surgery three months ago, the New York Post revealed Tuesday. In light of my own open gastric-bypass surgery five years ago, I have some idea what he's going through now.

For many, if not most, people who are obese, surgical intervention to reconfigure the stomach, or to reconstruct the entire digestive tubing, is the only way to reverse significant weight gain. Although most symptoms of obesity can be treated with medication, and many obese people can lead long and productive lives, surgery and the subsequent weight loss gives them a dramatically higher chance of improving the quality of their years.

In February, Christie asked a doctor to insert a silicone band around his stomach, limiting the amount of food he can eat at one setting. He will feel full more quickly, and the hormones ghrelin and leptin (among others) will signal satiety faster, making it harder for him to eat more than his stomach will allow. Weight loss will come rapidly. He has already lost 40 pounds in three months, the Post reports.

Lap-band surgery is getting safer, but it is not a one-and-done procedure. The stomach expands, pushing back against the silicone, and Christie will need more (though less invasive) surgeries to tighten the band over time. Had he chosen a more drastic intervention, like open gastric-bypass surgery, his weight loss would have been faster and perhaps even more permanent; that procedure still promises the highest rate of long-term success. In 2008, a doctor in Washington made a four-inch incision below by sternum, split open my abdominal cavity, and rewired the way I process food. Today, I weigh about 145 pounds -- down from 235 before the surgery.

Christie chose the lap-band procedure because the open surgery, which has a slightly higher risk of death but fewer long-term complications, is more dangerous for the morbidly obese, although a good surgeon can mitigate the potential problems. Full gastric-bypass surgery is pretty much irreversible, while the gastric band can be adjusted. Bypass surgery leaves the stomach intact, but all food is digested elsewhere, which can make for some pretty interesting episodes in a restaurant. There are certain foods that I can't eat, particularly those with high concentrations of sugar, and certain medicines, like aspirin, that will bore a hole in my intestines should I take them. Christie, in contrast, will be able to eat whatever he wants.

Post-surgery recovery can be painful, but the hardest adjustment is psychological. It may sound weird, but it isn't easy letting go of the fat person you once were. Your weight and appearance change rapidly; the person you stare at in the mirror becomes somewhat foreign to you. People around you treat you differently, and even within relationships, spouses and significant others often modify their own body-image expectations to keep pace with yours. I don't want to speculate on Christie's sex life, but one of the biggest sources of post-surgery psychological stress is the expectation people have that the quality of their sex life will improve quickly. (We do want our presidential candidates and governors to be sexually fulfilled, I would assume.)

Rapid weight loss changes mood, temper, and skin elasticity, will produce hair loss, may create vitamin imbalances, and even exacerbates (and may help create) other substance-abuse problems. It takes years to learn how to live as a skinny person. Many of us will never see ourselves the way we actually look. Some of us will feel guilty that we took the "easy" way out, although we know intellectually and physically that surgery was not easy, recovery was hard, and the dietary changes and psychological lessons we must practice daily are as challenging as your conventional fad-diet regimen. We just got a lucky press of the "reset" button, paying tens of thousands of dollars for the privilege.

Christie probably prolonged his life. Obesity's indicia are treatable, but the enormous stress of being a fat man in power could have precipitated a heart attack. By the time he runs (if he runs), all of the markers in his blood that should be up will be up, and all those that should be down will be down. Any sleep apnea he's suffered or diabetes he's had to treat will be gone.

I hope that if Christie runs for president, his good fortune in being able to sign this new contract will sensitize him in to the plurality who, despite changes to health-insurance policies, cannot get the surgery. It's not just a function of Medicare or the FDA approving it for a certain body mass index: The whole process takes a lot of time and is difficult to do if your job requires your regular presence without flexibility. Perhaps he will bring to the Republican Party -- as Mike Huckabee, the weight-struggling former governor of Arkansas did -- a realism and sensitivity about the tragedy of obesity among younger Americans who have significant stress in their lives and few resources to combat it.

If Americans embrace Christie and his journey, the stigma around these procedures will become less of a barrier to participation. Few high-profile Americans, with the exception of Al Roker, have openly talked about gastric bypass. I understand why Christie would want to keep the fact of his surgery secret for a while, because medical procedures are private. But I applaud him for coming out, as it were, as the most famous American to discuss his weight loss surgery.