Whether or not he lets himself be persuaded to run for president, Chris Christie needs to find some way to lose weight. Like everyone else, elected officials perform best when they are in optimal health. Christie obviously is not.

You could argue that this is none of my business, but I disagree. Christie’s problem with weight ceased being a private matter when he stepped into the public arena — and it’s not something you can fail to notice. Obesity is a national epidemic whose costs are measured not just in dollars and cents but also in lives. Christie’s weight is as legitimate an issue as the smoking habit that President Obama says he has finally kicked.

Yes, the basic arithmetic of calories ingested vs. calories expended is inescapable. But the science of weight control now takes into account the role that genetics might play, along with psychological factors that lie outside our conscious control. There are new options, including gastric surgery, beyond the dieting roller coaster — lose 40 pounds, gain it all back — that Christie says he has been riding for years.

Those who have lost weight and kept it off for extended periods, including former Arkansas governor Mike Huckabee, say they have succeeded by making proper diet and exercise part of their lives — not just unpleasant chores that have to be endured.

Politically, I disagree with Christie on almost everything. I’ll have plenty of opportunities to tell him why. Today, I’d just like to offer him a bit of unsolicited, nonpartisan, sincere advice: Eat a salad and take a walk.

Chris Christie’s big problem – The Washington Post