Obesity is one of the most important problems which threatens the global health. Healthcare organizations spend a
large amount of money to predict and treat obesity every year. The most common treatment for obesity is
concentrated on shaping a new lifestyle with more exercise and healthy diet. But a multitude of dieters fail. In this study, the role of cognitive processing in dieters` success or fail was investigated. Participants were
successful (N= 42) and unsuccessful (N= 45) dieters between 18 and 40 years old. Attentional bias, positive
implicit association, and working memory capacity were measured by dot-probe task, a modified
version of implicit association test (IAT), and N-Back task. Results indicated that unsuccessful dieters showed
greater attentional bias to (d= 0.69) and more food preferences for (d= 1.06) high-calorie food pictures.
Nevertheless, there was no significant difference in implicit associations for high calorie food and in working memory capacity between the groups. These results were congruent with some previous studies and they were discussed based on dual-processing model.