Preoperative eating behavior, postoperative dietary adherence, and weight loss after gastric bypass surgery

To investigate the relationship between preoperative eating behavior, postoperative dietary adherence and weight loss after gastric bypass surgery in a major, urban medical center with a comprehensive bariatric surgery program. Despite the significant weight loss and dramatic improvements in co-morbidities associated with bariatric surgery, a significant minority of patients appear to experience suboptimal weight loss. The reasons for this are not well understood, but the suboptimal weight loss is often attributed to preoperative psychosocial characteristics and/or eating behaviors, as well as poor adherence to the recommended postoperative diet.

A prospective investigation was performed of 200 female and male patients who were studied both preoperatively and 20, 40, 66, and 92 weeks postoperatively. All patients underwent either open or laparoscopic Roux-en-Y gastric bypass surgery. The measures were the percentage of weight loss, macronutrient intake, dietary adherence, and eating behavior.

Gender, baseline cognitive restraint, and self-reported adherence to the postoperative diet at postoperative week 20 were associated with the percentage of weight loss at postoperative week 92. Those high in dietary adherence had lost 4.5% more weight at postoperative week 92 than those low in dietary adherence.

Baseline cognitive restraint and adherence to the recommended postoperative diet were associated with the percentage of weight loss after gastric bypass surgery. These results suggest the potential utility of pre- and/or postoperative dietary counseling interventions to improve the postoperative outcomes.