Personality and Obese Body Mass Index

Abstract

This study investigated the relationship between obese range Body Mass Index (BMI) and personality variables as measured by the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). The sample consisted of 129 obese participants referred for preoperative psychological evaluation. Each completed an MMPI-2 and clinical interview. Multilevel linear regression analysis was used to assess the contribution of personality variables to the prediction of variance in obese range BMI. Age, Scale 9 (Hypomania), and Scale 4 (Psychopathic Deviate) emerged as statistically significant predictors of BMI. Each predicted 7.8%, 6.4%, and 3.1% of the variance of participant BMI, respectively, with a combined prediction power of 17.3%. F-scores for the final, best fit model, with age on Level 1 and Scale 9 and Scale 4 on Level 2, were statistically significant (p<.0009). Results suggest severely obese bariatric surgery candidates may be more prone to impulsivity, irritability, and instability. However, limited predictive power of MMPI-2 scales indicates restricted clinical utility.