Abstract Background Eating disorders (ED) are a public health concern due to their increasing prevalence and severe associated comorbidities. The aim of this study was to identify mental health and health behaviours associated with each form of EDs. Methods A case–control study was performed: cases were patients with EDs managed for the first time in a specialized nutrition department and controls without EDs were matched on age and gender with cases. Participants of this study filled self-administered paper questionnaire (EDs group) or online questionnaire (non-ED group). Collected data explored socio-demographics, mental health including anxiety and depression, body image, life satisfaction, substances and internet use and presence of IBS (Irritable Bowel Syndrome). Results 248 ED patients (broad categories: 66 Restrictive, 22 Bulimic and 160 Compulsive) and 208 non-ED subjects were included in this study. Mean age was 36.0 (SD 13.0) and 34.8 (SD 11.6) in ED and non-ED groups, respectively. Among patients and non-ED subjects, 86.7% and 83.6% were female, respectively. Body Shape Questionnaire mean score was between 103.8 (SD 46.1) and 125.0 (SD 36.2) for EDs and non-ED group, respectively ( p < 0.0001). ED patients had a higher risk of unsatisfactory friendly life, anxiety, depression and IBS than non-ED s (all p < 0.0001) Higher risk of anxiety, depression and IBS was found for the three categories of EDs. Higher risk of smoking was associated only with restrictive ED, while or assault history and alcohol abuse problems were associated only with bulimic ED. The risk of binge drinking was lower in all EDs categories than in non-ED. Conclusion This study highlights the common comorbidities shared by all EDs patients and also identifies some specific features related to ED categories. These results should contribute to the conception of future screening and prevention programs in at risk young population as well as holistic care pathways for ED patients. Plain English summary This case–control study evaluated mental health and health behaviours associated with the main categories of Eating Disorders (EDs). Cases were patients with EDs initiating care in a specialized nutrition department and controls without ED were matched on age and gender with cases. Self-administered paper questionnaires were filled by ED 248 patients (66 Restrictive, 22 Bulimic and 160 Compulsive) and online questionnaire by 241 non-ED controls. Body image satisfaction was significantly worse in ED patients than in controls. ( p < 0.0001). Dissatisfactory life, anxiety, depression and irritable bowel syndrome were more found in patients with all EDs categories than in non-ED ( p < 0.0001). Smoking risk was increased only in restrictive patients while and assault history and alcohol abuse was increased only in bulimic patients. These results highlight the global burden of ED and related comorbidities and provide useful information for future screening, prevention and care programs.