Heavy industry: there's no dearth of girth. But rather than expand, Durham's Rice Diet and its brethren watch their wait.

• Author: Gray, Tim
• Position: FEATURE

Longtime Durham residents easily spot the people who've come to lose weight. They see them huffing along the gravel trail encircling Duke University's East Campus, marked by their girth, their tentlike T-shirts and their new sneakers. They watch them squeezing through the aisles at Southpoint and Northgate malls. They notice them wedging into seats at Durham Bulls' games.

These are the clients of the city's three nationally known weight-loss clinics--Rice Diet Program LLC, Structure House Inc. and Duke University's Diet and Fitness Center. You might assume that the number of dieters in Durham is multiplying--driven by America's rampaging obesity--and that they're more visible around town.

Instead, the programs are not rushing to expand their campuses, launch satellite operations, plunge into franchising or try anything that would cause an MBA's adrenaline to spike. They're not in a hurry to capitalize on opportunity. For the time being, they're satisfied with what they are. Unlike their clients, they're happy with their size.

Even at the status quo, the business of losing weight is lucrative for the programs and for Durham. None of the clinics would reveal revenue, but dieters contribute about $30 million annually to the city's economy--paying the lofty fees that the programs charge, renting hotel rooms for weeks or months and buying everything from baseball tickets to the occasional illicit pizza. Slimmed-down alumni have appeared in Vogue and The New York Times and on Oprah and Good Morning America.

Public interest in weight loss is soaring. As anyone who has seen the funnel-cake line at the State Fair knows, America is fattening up. We've become a nation devoted to life, liberty and the pursuit of the all-you-can-eat buffet. According to the Centers for Disease Control, two out of three of us are overweight. Nearly a third are obese. In 2004, the agency declared obesity the No. 1 threat to the nation's health because of its link to diabetes, hypertension and a host of other ailments.

Those extra pounds could translate into larger profits for Durham's programs. The city draws about 3,000 dieters a year, from around the country and the world. It could attract many more. But presented with the chance to gorge on more of the $40 billion--at least--that Americans spend annually on dieting and weight loss, Durham's programs prefer to nibble.

The Rice Diet Program's boss says expansion would hurt his ability to serve his patients. "Once you get past about 70 to 80 people at a time--and we've been up to about 110--it's hard to give everybody the personal attention that you'd like," says Robert Rosati, a cardiologist who, with his wife, Kitty, owns and runs the program.

At Structure House, psychologist-owner Gerard Musante says he'll expand "when the conditions present themselves." He points out that he has added programs for diabetics and for folks who've had stomach-stapling surgery, even if he isn't planning new buildings or a facility elsewhere.

The Diet and Fitness Center--DFC for short--could grow more easily. Its building has plenty of...