Abstract
Social desirability is an individual difference characteristic that extends beyond biased responding to questionnaires. Social desirability has the potential to negatively impact treatment outcome including weight loss. This study examines the association between social desirability and percent body weight loss in thirty-six obese participants completing a behavioral weight loss program (BWLP). At baseline, higher social desirability was associated with: (1) greater reported weight control competence and weight loss self-efficacy, (2) the reported consumption of fewer calories, and (3) fewer reported dietary lapses and more positive attitudes toward their diet as recorded in lapse diaries. Higher social desirability was significantly associated with less weight lost at the end of the 6-month intervention. Weight control competence, self-efficacy, and abstinence violation effects mediated the social desirability and weight loss association. Individuals high in social desirability may overestimate their ability to succeed in a BWLP and may have difficulties accurately self-monitoring diet-related behaviors, thereby contributing to a poor weight loss treatment outcome.