This study investigated the Mediating Role of Cognitive Emotion Regulation in the Relationship between Brain-Behavioral Systems and eating behaviors among individuals with overweight and obesity by structural equation modeling. The statistical population consisted of women and men suffering from overweight and obesity who went to health centers, and sports clubs of Tehran in autumn and winter of 2017. Using convenient sampling method, 500 of them were selected. Duct behavior questionnaire (Van Strien, Frijters, Bergers & Defares, 1986), Cognitive Emotion Regulation (Garnefski & Kraaij, 2006), Measurement of Inhibition / Behavioral Activation Systems (Carver & White, 1994) were used for gathering data. Findings showed that maladaptive cognitive emotion regulation relatively mediated the relationship between brain-behavioral systems, and eating behaviors. Finally ,it was determined that the model (After the modification of model based on statistical results) had a better fit to the observed data. And predictive variables significantly explained 53 percent of eating behaviors. Brain-behavioral systems and emotional cognitive regulation play an important role in predicting eating behaviors in overweight and obese patients, so their role should be considered in prevention and treatment programs.