Obesity is a chronic, multifactorial disease. There are a number of neurocognitive and behavioral mechanisms that contribute to overeating, or eating past nutritional needs, which can lead to obesity. Dysregulated dopamine-based reward circuitry has been implicated in overeating and obesity. We have different methods to modify brain function. One of these methods is transcranial Direct Current Stimulation (tDCS). In this research we want to assess the effect of tDCS on brain function in obese people. 19 overweight and obese individuals were assigned to experimental (tDCS) and control (Sham tDCS) groups based on their ages and BMI. All participants completed a cognitive task (Flanker test) while their EEG were recorded before and after the treatment. They received 10 treatment session in 2 weeks. The results of Covariance Analysis showed that tDCS can significantly decrease the amplitude of P200 and P300 component and increase the amplitude of N200 component in obese individuals. The results showed that applying tDCS can change brain function in the brain of obese people.