Obesity is a global epidemic and a major contributor to some of the leading causes of death.

Although research on overweight and obesity is constantly increasing, to date, in the Italian panorama, there is a lack of (A) rigorous psychological measurement tools of obesity-related constructs and (B) analysis of the relationships between constructs (and indicators) involved in the development and maintenance of overweight and obesity.

The present study aims to examine the psychometric properties of the main questionnaires for the assessment of eating behaviors in 3 groups of subjects (1) the general population (control group); (2) subjects with obesity without a comorbid diagnosis of an eating disorder; (3) subjects with obesity and a comorbid diagnosis of an eating disorder.

Participants were selected in the main rehabilitation centers for the treatment of obesity and eating disorders (sample of subjects with obesity) and through an online survey (community sample). The survey lasted about 30 minutes and - together with selected demographic and biomedical information - required the completion of the following self-report measures: the Binge Eating Scale (BES); the Modified Yale Food Addiction Scale version 2 (mYFAS 2.0); the Repetitive eating questionnaire (Rep-EAT); the Measure of Eating Compulsivity (MEC); the Addiction-like Eating Behavioural Scale (AEBS); the Three Factor Eating Questionnaire 18 (TFEQ-18); the Eating Disorders Examination Questionnaire-Short Form (EDEQ-SF); the Palatable Eating Motive Scale (PEMS); the Weight Sigma Questionnaire (WSSQ); the Emotional Eating Scale (EES); the Somatic Symptom Scale 8 (SSS8).

Before administration, all questionnaires were first translated from English (their original language) to Italian by two bilingual translators, independently - then back-translated into English by another independent translator whose mother tongue was English to ensure equivalence between the translations. Following, a purposive sample of respondents was asked to fill in the final version of each measure in order to assess its items' comprehensibility.

In order to avoid halo effects, the questionnaires were presented to the subject in random order.

The responders could withdraw the administration at any time, and contact a psychologist independent from the study in case of perceived emotional distress.

Inclusion Criteria:

• BMI > 30 kg/m2 (clinical sample)
• Diagnosis of an eating disorder (clinical sample)
• age range 18-75 years
• Italian mother tongue
• written and informed consent to participate

Exclusion Criteria:

• visual impairing
• neurological problems
• alcohol/drug abuse

Subjects with obesity with/without an eating disorder AND the general population (non clinical)