Thus, this study was designed to achieve the following objectives: i) to compare the domains of eating behavior assessed by the Three Factor Eating Questionnaire (TFEQ-21) and eating disorder symptomatology through the Eating Disorder Examination Questionnaire (EDE-Q) in FM and healthy subjects; ii) to examine the relationship between the role of eating behavior with the serum BDNF and the serum S100B protein. This evidence concerns the gene BDNF and eating disorder.