Specific personality traits, as assessed by the Temperament and Character Inventory (TCI), have been identified in individuals with obesity, but their association with binge and/or night eating has scarcely been reported. Indeed, our systematic search of Medline (1987 to 2013) yielded only five studies on the issue. Taken together, they suggest that personality traits do not have any significant role in determining body mass index, and therefore obesity class. However, obese individuals, in comparison with normal weight individuals, do seem to have a distinctive personality profile, characterized by low self-directedness and cooperativeness, and obese individuals with binge eating show lower self-directedness than those without. Moreover obese individuals with binge eating and/or night eating share a temperament profile characterized by high novelty-seeking and harm-avoidance, two traits also observed in other eating disorder categories and in clinical depression. Future longitudinal studies are needed to investigate the role of personality traits in the onset of binge eating and night eating in obese individuals, and to clarify their influence, if any, on treatment outcomes. Such information will enable us to determine whether the evaluation of personality traits should be included in the comprehensive assessment of obese individuals.
Keywords: Binge eating disorder; Eating disorders; Night eating syndrome; Obesity; Personality; Personality traits.