Washington ? Remember when everybody wanted to live in Fat City? Remember when Fat City was the imaginary slang capital of the land of plenty? This was the place where your cup runneth over.

Well, nobody seems to regard it as a compliment anymore.

In case you missed it, Detroit was given the dubious honor this year of being named the fattest city in America. The title was awarded by Men’s Fitness, a magazine of pecs and abs. How did it portray the winner? As a beer-bellied blue-shirted slob eating a bucket of donuts and against a backdrop of — ta da — hub caps.

Not a very pretty picture, to put it mildly. Kwame Kilpatrick, the 6-foot-4, 300-pound mayor of Detroit, wasn’t exactly thrilled at being No. 1. But it’s an image that has stuck. Motown as Fat City? This just may be the moment when we acknowledge that the culprit in the battle of the bulge has more than a giant maw. It has four wheels.

What did Mayor Kilpatrick say when he heard that the city had maxed out? “We love our cars.” He said it as sheepishly as the mayor of Philadelphia might say, “we love our cheesesteaks.” Now the auto industry is rolling out a car called Titan while we are driving ourselves to Obesity.

The Detroit Moment must delight the public health gurus who agree that the car is a major ingredient in the incredible growing American, on an enemies list right beside Big Macs. Indeed, one of the reasons Motown moved from third to first place in the heavyweight division was an increase in commuting time.

Of course in fairness, rather than in fitness magazines, we wouldn’t be crowning Fat City. We’d be crowning fat suburb or fat exurb. Last fall we were treated to a sheaf of studies showing that the waistline expands with the distance you live from neighbors or from work or from the market. The farther out you live the less you walk, the more you drive, the more you weigh.

The Robert Wood Johnson Foundation redefined sprawl itself as a public health menace. It’s not just the landscape that disappears with each cul-de-sac subdivision, it’s the body shape. Urbanites are on average six pounds thinner than their suburban cousins.

The number of miles an American drives has doubled since 1963 and the number of overweight children between 6 and 11 has doubled since 1973. Kids today spend about an hour a day in cars, not counting the school bus. One of life’s great ironies is that so many families move to the exurbs for a better lifestyle for the kids. Whereupon parents turn into chauffeurs and kids get strapped into car seats whenever we need a bottle of milk.

The only one I’ve found who thinks the automobile can be a diet aid is an imaginative Connecticut inventor named Yefim Kriger, who won a patent for a gizmo that can weigh drivers — and harass them when they’ve overeaten with admonitions like: “You ate too much! Don’t do it next time!”

For a long time, scientists have told us that the car is to the environment as the cigarette is to the human body. Today, smoking is down but gas guzzling is up. They’ve had little luck getting Americans to slim down their fuel intake. Instead they’ve bulked up their cars.

If we don’t care that every gallon of gas puts 20 pounds of carbon dioxide in the air, maybe we’ll care that it puts those pounds on the hips. Americans may have a love affair with the car, but we have an obsession with weight loss. We go from the Zone Diets to South Beach and follow Atkins beyond his grave. We go high and low, carb and fat. At any given moment 45 percent of American women and 30 percent of American men are trying to lose weight.

Instead of lecturing Americans to ease up their driving for the sake of the environment, we could market it as a weight loss activity. Instead of slapping stickers on SUVs impugning the politics of the owners, we could slap warning labels on cars saying: This Vehicle Will Make You Fat. We could form Gas Watchers; instead of weighing in on a scale once a week, we’d have to report our odometer.

Want to lose six ugly pounds, reduce sprawl and make sidewalks our most important protect? Put aside your Safari, park your Defender, trade in your Explorer for walking shoes. Now that’s Phat City.

– Ellen Goodman is a columnist for Washington Post Writers Group.