The impression from Swedish eating disorder (ED) units is that there has been an increase in the number of overweight or obese patients. There is, however, no research studying whether these patients differ from normal-weight ED patients in other aspects than weight. Differences between normal-weight and overweight or obese ED patients could indicate that these groups of patients need different treatment approaches. The aim of this study was to investigate possible differences between normal-weight and overweight or obese ED patients in psychiatric and psychological pre-treatment variables. The study was based on data from a Swedish quality assurance system for ED care. In total, data from 3,798 adult patients with body mass index ≥ 18.5 were used. The sample included all normal-weight ED diagnoses. Significant differences between normal-weight, overweight and obese patients were found for five of eight self-image variables, for all eating disorder examination questionnaire subscales and for most key diagnostic symptoms. However, effect sizes were mostly small or very small. Overweight or obese patients did not display greater levels of psychiatric psychopathology than normal-weight patients. They did, however, show a tendency towards more negative self-image and more severe ED symptoms than normal-weight patients. Overweight and obesity in ED patients are thus not only associated with physical health problems, but also with mental health issues. Further studies are required to investigate the clinical relevance of these findings.
