May 1, 2006 -- Most weight loss surgeries are performed on patients who are morbidly obese, but new research suggests that one surgical option may be a safe and effective treatment for people who have much less weight to lose.
The study compared outcomes among mild to moderately obese people who either had laparoscopic adjustable gastric banding surgery or who followed an intensive weight loss program that did not include surgery.
In this surgery, an adjustable band was placed around the stomach via small incisions in the abdominal wall with the use of a special camera to help place it.
After two years, patients who had the gastric banding lost an average of 21% (45 pounds) of their initial body weight, compared to a 5.5% (12 pounds) weight reduction among patients whose intervention included strict calorie restriction, weight loss drugs, and other lifestyle interventions.
If confirmed, the findings could lead to a major shift in thinking about who is and is not a candidate for weight loss surgery, the study researchers say.
"It won't happen overnight," Paul E. O'Brien, MD, tells WebMD. "But in the United States alone you have 60 million people who are [mildly obese or heavier] and they suffer a wide range of health problems because of their weight. This is a very safe surgery that could be used to help many more people."
What's in a BMI?
The researchers measured obesity by calculating the patients' body mass index (BMI), a standardized measure based on height and weight.
A BMI of 18.5 to 24.9 is considered normal weight. People are considered overweight if their BMI is 25 to 29.9, and obese if they have a BMI of 30 or more.
A BMI of 40 or more is considered morbidly obese. To translate BMI to the bathroom scale:
- A 5-foot-4-inch person would be considered overweight if they tip the scale at 175 pounds (BMI = 30), obese if they weigh 205 pounds (BMI = 35), and morbidly obese if they weigh more than 235 pounds (BMI = 40).
- Someone who is 5 foot 7 inches and weighs 190 pounds would be considered overweight, while the same person would be considered obese at 194 pounds, and morbidly obese at 255 pounds.
- A 6-foot tall person is considered overweight if they weigh between 185 and 221 pounds, obese if they weigh between 222 and 294 pounds, and morbidly obese at 295 plus.
- Carrying 30 to 35 extra pounds is the difference between normal weight and obesity for most adults.
'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 heart disease known as metabolic syndrome. 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.
Tsai is medical director of the Weight and Eating Disorders Program at the University of Pennsylvania School of Medicine.
"Doctors and patients should not forget that you can achieve weight loss with dietary changes and exercise," he says. "There are effective treatments for weight loss that involve less risk than surgery."