'Obesity Gray Zone'
People with BMIs of between 30 and 35 are generally considered to be mild to moderately obese, and are not often considered for weight loss surgery.
O'Brien refers to this as the "obesity gray zone."
The researchers chose people in this weight range for the study because they felt that it would be unethical to deny heavier people the option of weight loss surgery, he says.
Eighty people were enrolled in the study and patients were randomly assigned to treatment with either laparoscopic adjustable gastric banding (LAGB) or the nonsurgical weight loss program.
At the end of two years, the LAGB group lost about four times as much body weight as the nonsurgical group. Only one patient in the surgical group, compared with eight in the nonsurgical group, had a condition that put them at risk for diabetes and known as . At the start of the study, metabolic syndrome was seen in 15 participants in each group.
The study is published in the May 2 issue of the journal Annals of Internal Medicine.
No Surgery Is Risk-Free
In an accompanying editorial, Adam Tsai, MD, and Thomas Wadden, PhD, of the University of Pennsylvania called the study "the strongest evidence to date" indicating the benefits of surgical over nonsurgical approaches to weight loss.
But Tsai tells WebMD that the findings leave many questions unanswered and must be confirmed before it is clear that gastric banding is both effective and safe for the treatment of mild to moderate obesity.
"If you agree that anyone with a BMI of 30 or more is now a candidate for surgery, that is fully a third of the people in this country," he says. "I don't think anyone would suggest that a third of our country should be having this procedure.""
O'Brien says LAGB is much safer than more invasive bariatric surgeries. Tsai says while that may be the case, no surgical procedure is risk-free.