Objective: Personality influences lifestyle behaviors. Therefore, certain personality traits could contribute to obesity and the response to behaviorally based weight loss therapy. Purpose: The aims of this study were to test the hypothesis that personality characteristics differ between lean and obese persons in the community, obese persons in the community and obese persons seeking weight loss therapy by enrolling in a comprehensive weight loss program, and in obese persons who were successful and unsuccessful in achieving behavioral therapy-induced weight loss. Methods: The Temperament and Character Inventory was administered to 264 lean ( body mass index (BMI) < 25 kg/m(2)) and 56 obese (BMI >= 35 kg/m(2)) subjects from the St Louis community and 183 obese patients ( BMI 44710 kg/m2) enrolled in the Washington University Weight Management Program (WUWMP), which involved weekly group behavioral therapy and diet education sessions for 22 weeks. Results: Compared with lean subjects, obese subjects in the community scored higher in novelty seeking (19.7 +/- 5.9 vs 16.2 +/- 6.0, P < 0.05), lower in Persistence (4.1 +/- 1.8 vs 4.8 +/- 1.7, P < 0.05) and lower in self-directedness (32.1 +/- 7.6 vs 34.3 +/- 6.6, P < 0.05.) Patients enrolled in the WUWMP scored higher than obese persons in the general population in both Reward Dependence (17.1 +/- 4.2 vs 15.7 +/- 4.3, P < 0.05) and cooperativeness (36.9 +/- 5.4 vs 34.5 +/- 6.2, P < 0.05). Patients who were successful in losing weight (410% weight loss) after 22 weeks of behavioral therapy scored lower in novelty seeking than those who were unsuccessful in losing weight (< 5% weight loss) (17.6 +/- 5.9 vs 20.2 +/- 5.9, P < 0.05). Discussion: These results suggest that personality traits differ between lean and obese persons, and between obese persons who enroll and who do not enroll in a comprehensive weight management program. Moreover, high scores in novelty seeking are associated with decreased success in achieving behavioral therapy-induced weight loss.
