**2. Experimental Section**

#### *2.1. Participants*

The sample consisted of 62 male participants diagnosed with ED (16-AN, 12-BN, 15-BED, 19-Other Specified Feeding or Eating Disorder (OSFED)), 656 female ED patients (140-AN, 236-BN, 100-BED, 180-OSFED), and a HC group, 286 females and 78 males, without a history of ED. The clinical groups were consecutively referred for assessment and treatment at the Eating Disorders Unit within the Department of Psychiatry at Bellvitge University Hospital in Barcelona, Spain. All patients were diagnosed according to the DSM-5 [37] criteria and assessed by senior clinicians specialized in ED. All HC came from the same catchment area as the patients. Participants were recruited between May 2013 and July 2018. In accordance with the Declaration of Helsinki, the present study was approved by the Ethics Committee of our institution (The Clinical Research Ethics Committee (CEIC) of Bellvitge University Hospital). All the participants provided signed informed consent.

#### *2.2. Assessment*

Eating Disorder Inventory-2 (EDI-2) [45]. This is a reliable and valid 91-item multidimensional self-report questionnaire that assesses different cognitive and behavioral characteristics of eating disorders: Drive for thinness, body dissatisfaction, bulimia, ineffectiveness, perfectionism, interpersonal distrust, interoceptive awareness, maturity fears, asceticism, impulse regulation, and social insecurity. This instrument was validated in a Spanish population [46]. Internal consistency was excellent in our sample (α = 0.97 for the total scale).

Symptom Checklist-90 Items-Revised (SCL-90-R) [47]. This is a 90-item questionnaire that is widely used for assessing self-reported psychological distress and psychopathology. The test is scored on nine primary symptom dimensions: Somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism, and three global indices: Global Severity Index (GSI), Positive Symptom Total (PST), and Positive Symptom Distress Index (PSDI). This instrument was validated in a Spanish population [48]. Internal consistency was excellent in our sample (Cronbach's alpha, α = 0.98 Cronbach's alpha).

Temperament and Character Inventory–Revised (TCI-R) [49]. The TCI-R is a 240-item questionnaire with a five-point Likert scale format. This questionnaire is a reliable and valid measure of four temperaments (harm avoidance, novelty seeking, reward dependence, and persistence) and three character dimensions (self-directedness, cooperativeness, and self-transcendence). This questionnaire was validated in a Spanish adult population [50]. Cronbach's alpha for the current sample ranged from good (α = 0.81 for "novelty seeking") to excellent (α = 0.99 for "persistence").

Difficulties in Emotion Regulation Scale (DERS) [51]. The DERS assesses emotion dysregulation across six subscales: (a) Nonacceptance of emotional responses, (b) difficulties in pursuing goals when having strong emotions, (c) difficulties controlling impulsive behaviors when experiencing negative emotions, (d) lack of emotional awareness, (e) limited access to emotion regulation strategies, and (f) lack of emotional clarity. Higher scores indicate more difficulties in emotion regulation. The Spanish version was validated in an adult population [44], and excellent internal consistency was found in the study sample (α = 0.96 for the total scale).
