"I don't function well in group therapy," he said, adding that he had tried Weight Watchers and hated the meetings.

The 64-year-old accountant wanted more science and less socializing. He also wanted a plan that addressed all of his concerns — including his escalating cholesterol — not just his belly.

Now he sees Dr. Jennifer Warren, one of a small but growing number of physicians nationally who are specializing in weight management after their family practices were overwhelmed by patients with weight-related health problems.

"Primary care is preventive medicine. This really is the ultimate preventive medicine," said Warren, who left her general practice in February to open Physicians Healthy Weight Center, an obesity clinic in Hampton.

"That's what got me started in this direction," the 39-year-old said in a recent interview. "So many of the medical problems I was treating in family care were weight-related."

Three weeks into his treatment, Martin's cholesterol was down and he had lost 12 pounds, thanks to low-dose appetite suppressants and calorie-cutting.

With two-thirds of Americans overweight and at greater risk for heart disease, diabetes and certain cancers, many in the medical community want to redefine the role doctors have in helping people slim down.

Doctors say the pressures of general practice — which can limit time with patients to mere minutes — and a lack of specialized training make it difficult to treat obesity in a primary-care environment.

They say treatment involves not only creating individualized diet and fitness plans, but also assessing serious health concerns and addressing the underlying emotional and psychological issues that contributed to the weight gain.

Though often associated with gastric surgery, a procedure that reduces the size of the stomach, so-called bariatric medicine includes a gamut of treatments, from special diets to counseling to prescription drugs.

The impetus for change comes mostly from medical schools, according to Dr. George Blackburn, associate director of Harvard Medical School's nutrition division.

Medical students and young doctors are demanding to know more about nutrition and weight management, which previously was absent from most curricula, he said.

"We always ask physicians whether they see obese patients in the practice. They just laugh at us and say at least half," said Beth Little, executive director of the American Society of Bariatric Physicians.

"They used to say there was nothing they could do. Now they are just taking it a lot more seriously."

Head counts of bariatric physicians are imprecise; Little's group has 1,104 members, an increase of 165 from two years ago. The American Board of Bariatric Medicine has 236 certified physicians, and expects to add another 50 this year.