Can rich French sauces help you lose weight? New Orleans says oui.

As America's most obese city, New Orleans has long been ripe for a fad diet book. Still, Sugar Busters! has become such a craze that it has even swept Creole institutions like Antoine's, Galatoire's and Commander's Palace, places known for fried oysters, rich French sauces and boudin sausages. The secret to Sugar Busters! is that the diet is as free and easy as New Orleans itself: you can eat just about anything you want.

Butter, cream, beef and cheese are all allowed in moderate portions. What's the catch? Just cut out refined sugar. Carrots, white potatoes and processed grains like white flour, which contain starches that quickly break down into sugar, are also forbidden. (Sweet potatoes, somewhat counterintuitively, are okay.)

The authors,three New Orleans doctors and a local businessman, assert that eliminating sugar drives down insulin levels in the bloodstream, which in turn keeps the body from storing fat. Some dieters are comparing Sugar Busters! to Barry Sears's The Zone.

Not everyone buys the Sugar Busters! premise, however. "The authors don't identify their scientific research," says Barbara Dixon, a spokesperson for the American Dietetic Association in Baton Rouge, Louisiana. "I have a problem with the lack of restrictions on animal fat and protein in the diet."

Such criticism hasn't damaged the success of Sugar Busters! The authors have sold 170,000 copies since they published the book at their own expense two years ago. Ballantine recently acquired the title, adding meal plans and recipes from New Orleans chefs like Emeril Lagasse (who contributed his filet mignon stuffed with blue cheese); the revamped book has just been released nationally.

In New Orleans, meanwhile, even old-line restaurants are highlighting Sugar Busters! items on their menus. Take Galatoire's. Without cracking a smile, waiters serve shrimp remoulade (in a heavy mustard sauce) as a dieter's choice.

"The other day, a guy brought in his own sweet potatoes so he could have our Brabant potatoes prepared the Sugar Busters! way," reports David Gooch, the general manager of Galatoire's. Gooch was happy to adapt the classic recipe for fried potato cubes with melted butter. "One of the Sugar Busters! authors is my brother-in-law," he says with a smile.