Severely obese patients who have lost significant amounts of weight by changing their diet and exercise habits may be as successful in keeping the weight off long-term as those individuals who lost weight after bariatric surgery, according to a new study.

While weight loss and maintenance were comparable between the two treatments, patients who relied on non-surgical methods had to work harder over a longer duration to maintain their weight losses, said researchers from The Miriam Hospital's Centers for Behavioral and Preventive Medicine.

"Our findings suggest that its possible to maintain large weight losses through intensive behavioral efforts, such as changing your approach to eating and exercise, regardless of whether you lost weight with bariatric surgery or through non-surgical methods," said lead author Dale Bond, PhD, of The Miriam Hospital's Centers for Behavioral and Preventive Medicine. "Behavioral modifications and lifestyle changes are critical components to long-term weight loss maintenance."

Researchers matched each surgical patient with two non-surgical patients through the National Weight Control Registry. All participants – 315 total – lost an average of 124 lbs and had maintained their weight loss for an average of 5.5 years at the beginning of this two-year study.

Individuals were surveyed at both the start of the study and at the one-year follow-up about weight-maintenance behaviors (including food records and physical activity levels) and various psychological factors (such as dietary restraint, feelings of hunger and food cravings, stress and depression). Weight-related information was collected at both the one- and two-year follow-up.

There were no significant differences in the caloric intake or the amount of weight regain between the surgical and non-surgical groups; both regained an average of about four lbs. each year. However, researchers identified behavioral differences between the two groups, with bariatric patients reporting greater fat and fast food consumption, less conscious control over their eating and higher incidences of depression and more stress than non-surgical patients.

Similar differences were observed with physical activity behaviors. Only one-third of the surgical group reported engaging in a level of physical activity consistent with recommendations for preventing weight regain compared with 60 percent of the non-surgical group.

The researchers note that susceptibility to cues that trigger impulsive overeating was the only behavior associated with a greater risk of weight regain in both groups.

"These findings underscore the need for eating and activity interventions focused on bariatric surgery patients," said Bond, who is also a research fellow in psychiatry (weight control) at the Warren Alpert Medical School of Brown University. "Future research should focus on ways to increase and maintain physical activity and better monitor psychological parameters in bariatric surgery patients to facilitate optimal long-term weight control."

The study was supported by a grant from the National Institutes of Health and was publishedonline by the International Journal of Obesity.