Date of Award

Summer 2016

Document Type


Degree Name

Doctor of Philosophy (PhD)


Psychology and Behavioral Sciences

First Advisor

Donna Thomas


Obesity has become an epidemic in the United States that can result in problems in multiple areas of an individual's life. Bariatric surgery has been shown to be an effective weight loss treatment for obese and morbidly obese individuals; however, although many individuals obtain long-term weight loss success after surgery, there is a percentage of patients who do not obtain the expected weight loss or end up regaining the weight they had initially lost. In an attempt to identify those who may be at risk for poorer results after bariatric surgery, most surgeons require that an individual undergo a psychological evaluation before they are approved for surgery. Previous research has attempted to identify specific factors assessed in the psychological evaluation that may be used to identify those patients who are at risk for poorer surgery outcomes; however, results have been contradictory. This study examined whether specific psychological variables obtained during the psychological evaluation for gastric bypass surgery, specifically, scores on measures of disordered eating behavior, anxiety, and depression, could be used to predict short and long-term success post-surgery, as measured by the percentage of excess weight loss (EWL). This study also examined the role that behaviors engaged in after surgery: binge eating, night eating, grazing, and alcohol use play in longer term bariatric surgery success. The results of the present study did not support the majority of the hypotheses. Anxiety and depression was not found to be a predictor of EWL in the majority of hypotheses; however, anxiety post-surgery was found to predict EWL at two points post-surgery. There were some interesting significant findings when examining the variables measuring disordered eating and health. Results showed that the Binge Eating Scale and the Night Eating Questionnaire were negatively correlated with the percentage of excess weight loss at various points post-surgery. The results also showed that excess weight loss was correlated with physical and mental health. Additionally, the Grazing Questionnaire was found to be positively correlated with the Binge Eating Scale.