Item	Description
1	Representative sampling procedures (Yes: 1; No: 0)
2	The inclusion and exclusion criteria of participants were suitable to represent clinical or at risk population for MD and ED (Yes: 1; No: 0)
3	Dropouts were similar in sociodemographic characteristics to those of the final sample (completers) (Yes: 1; No: 0; Unable to determine: 0)
4	The measurement instrument used to assess MD show good psychometric properties (validity and reliability) in the sample of study (Yes: 1; No: 0; Unable to determine: 0)
5	The measurement instrument used to assess ED shows good psychometric properties (validity and reliability) in the sample of study (Yes: 1; No: 0; Unable to determine: 0)
6	The assessment of DM and ED was not dichotomized (Yes: 1; No: 0)
7	Absence of reporting bias: results for all MD and ED instruments described in “Methods” section were reported (Yes: 1; No: 0)
8	The statistical test used to assess the relationships between MD and ED was appropriate to the data (non-parametric methods vs. parametric methods) (Yes: 1; No: 0; Unable to determine: 0)
9	Absence of private financial support (Yes: 1; No: 0)
10	Statistical power: sample sizes have been calculated to detect an effect (Yes: 1; No: 0; Unable to determine: 0)

Note. The methodological quality checklist consisted of 10 criteria with a dichotomous response scale. The presence of the criterion is given 1 point and its absence 0 points. The total score was 10 points. MD: muscle dysmorphia; ED: eating disorders.