60% of Bariatric Patients Keep Weight Off
April 16, 2010 -- Nearly 60% of bariatric surgery patients are successful at long-term weight loss, according to a new study from Switzerland with an eight-year follow-up.
However, disordered eating behaviors, such as binge eating or night eating, lingered for 51% of the 80 women who completed the entire study, says study author Maaike Kruseman, MPH, RD, professor of nutrition and dietetics at the University of Applied Sciences Western Switzerland, Geneva.
The weight loss results, however, were a pleasant finding for researchers and patients, Kruseman says. ''In our center, most patients have a long history of failed diets, so successful weight loss lasting longer than a couple of years was an incredibly good result," Kruseman tells WebMD in an email interview.
Disordered eating after the bariatric or weight loss surgery is not usually documented on a routine basis, she says, but she suspects it is common. "The bypass takes care of one aspect of the patient's problems, but if disordered eating is present before the operation, it will not [usually] disappear by itself, or only rarely," she says.
That finding, she says, points to the need for long-term follow-up of bariatric surgery patients by a team of health care providers that can tend to medical and psychological needs.
The study appears in the Journal of the American Dietetic Association.
Bariatric Surgery Study
Initially, 141 patients (including 10 men) were enrolled in the study. The average age was 40. At the study start, the average weight was 274 pounds and the average body mass index (BMI) was 46.
Candidates for bariatric surgery have a BMI of 40 or above, according to the American Society for Metabolic & Bariatric Surgery, or a BMI of 35 or more with an obesity-related disease, such as type 2 diabetes or heart disease. A BMI of under 25 is deemed healthy.
All participants had the type of bariatric surgery known as the Roux-en-Y gastric bypass between 1997 and 2002. In the procedure, the gastric bypass is achieved by reducing the size of the stomach so that a small gastric pouch is created. The small pouch size leads to reduced food intake.
At the 8-year mark, 80 participants, all women, were still taking part in the study. Of those, 47, or 59%, had achieved an excess weight loss of 50% or more, considered successful.
At the end of the follow-up, researchers also found:
- Fifty-three patients or 67% had a BMI under 40; 16 or 20% had shifted from the obesity category to overweight. One woman achieved a normal BMI, under 25.
- The average daily calorie intake went from 2,355 at the study start to 1,680 for the 80 participants who finished the study.
- Younger women were more likely to maintain the successful weight loss.

