Objectives. - In western countries, obesity is currently considered as a major public health issue, mostly in relation with bulimia addiction. While meeting obese subjects with bulimia, one can hear a complaint and a suffering expressed as an acute pain of body dissatisfaction. These subjects feel ashamed and conclude that their body dissatisfaction should have a large impact on their self-esteem. The care requested is more related to this suffering as to its impact on health. To better understand this demand for restoring self-esteem by losing weight, we undertook to assess the actual effects of weight loss. The aim of our study was to measure the effects of medical treatment or psychological support on self-esteem and body dissatisfaction for obese subjects with bulimia. Patients or materials and methods. - A follow-up study was performed on a cohort of 41 obese and bulimic patients who had requested a "bypass" surgery for obesity (bariatric) or a treatment by cognitive-behavioural therapy (CBT) at the addiction centre of the University Hospital (Centre Hospitalier Universitaire, or CHU), at Nice. The study took place between May 2007 and September 2010 with patients aged 18 to 54 years who passed the BULIT bulimia test. Self-esteem (SEI) and body dissatisfaction (EDI) were measured for each patient before and after treatment. Quantitative variables were derived from the questionnaires completed by the patients and checked by medical staff. The relationship between two quantitative variables were studied by simple linear regression methods. Results. Scores of BD-EDI body dissatisfaction and RSES are very low before treatment either by bypass or CBT. Treatment with by bypass surgery results in a relatively large loss of weight. Cognitive and Behavioral Therapies also allow patients to lose weight even though the average loss is less important. BD-EDI scores on body dissatisfaction are significantly improved by weight loss either by bypass or CBT. On the contrary, we notice that the RSES self-esteem score is not much enhanced by effective loss of weight, either by bypass or CBT. It rather remains unchanged. We further investigated whether there could exist a significant dependency between the decrease of body dissatisfaction (equal to 7.8 in the average) and the change of self-esteem (equal to -0.3 in the average). We calculated a correlation coefficient of 0.29, which is very low. Further, the hypothesis of a dependency between decrease of body dissatisfaction and change of self-esteem could be rejected. Conclusions. The main result of this clinical trial is that low self-esteem is not directly related to body dissatisfaction in bulimic disorder cases after a loss of weight. Taking into account this experience of indignity connected to low self-esteem may provide significant leverage to avoid relapses and failures in patient follow-up after bypass surgery and CBT. Despite the rational and convincing discourse of a shame felt by the subject because of his obesity and of social rejection, we believe that obesity results from an initial shame. Therefore, self-esteem is not really improved by a loss of weight. In this sense, the shame of one's body is an illusion for the subject itself. (C) 2015 Elsevier Masson SAS. All rights reserved.