Patients Lacking Sustainable Long-Term Weight Loss after Gastric Bypass Surgery Show Signs of Decreased Inhibitory Control of Prepotent Responses

Background A considerable number of bariatric patients report poor long-term weight loss after Roux-enY gastric bypass (RYGB) surgery. One possibility for an underlying cause is an impairment of cognitive control that impedes this patient group's dietary efforts. Objective To investigate if patients having either poor or good weight loss response, similar to 12 years after RYGB-surgery, differ in their ability to inhibit prepotent responses when processing food cues during attentional operations-as measure of cognitive control. Methods In terms of weight loss following RYGB-surgery, 15 'poor responders' and 15 'good responders', matched for gender, age, education, preoperative body mass index, and years since surgery, were administered two tasks that measure sustained attention and response control: a go/no-go task and a Stroop interference task; both of which are associated with maladaptive eating behaviours. Results The poor responders (vs. good responders) needed significantly more time when conducting a go/no-go task (603 +/- 134 vs. 519 +/- 44 msec, p = 0.03), but the number of errors did not differ between groups. When conducting a Stroop interference task, poor responders read fewer inks than good responders (68 +/- 16 vs. 85 +/- 10 words, p = 0.002). Conclusion Patients lacking sustainable weight loss after RYGB-surgery showed poorer inhibitory control than patients that successfully lost weight. In the authors' view, these results suggest that cognitive behavioral therapies post-RYGB-surgery may represent a promising behavioral adjuvant to achieve sustainable weight loss in patients undergoing this procedure. Future studies should examine whether these control deficits in poor responders are food-specific or not.