The main purpose of the article is to determine the effectiveness of cognitive- behavioral therapy in the treatment of high school girls afflicted with obesity. This study, as a type of multiple baseline design, was carried out in two phases (losing weight and keeping weight) on four female high school students afflicted with obesity. Before the treatment sessions started, special tools such as evolutionary checking list and eating disorder questionnaire were used. At the beginning of each treatment session, sick people were weighed and their data were shown through data visual analysis, charting and calculation of the recovery rate. The results showed that cognitive - behavioral therapy of obesity was effective in losing and keeping the weight of the obese adolescents.

Keywords: Obesity, body mass index, Cognitive-behavioral treatment