Chewing in adolescents with overweight and obesity: An exploratory study with behavioral approach.  Physiological and behavioral aspects of masticatory function may have an impact on nutritional status, which has been little studied. The aim was to perform a comprehensive evaluation of objective, subjective and behavioral aspects of masticatory function in 231 adolescents, aged 14-17 years and compare these parameters between normal-weight (n = 115) and adolescents with overweight/obesity (n = 116). Objective aspects were examined by the Oro-facial Myofunctional Evaluation-expanded protocol (OMES-e), determining the masticatory type, chewing time/frequency, abnormal movements, and other; masticatory performance (color changeable chewing gum) and bite force were also explored. The subjective and behavioral evaluations were assessed using the Quality of Mastication Function Questionnaire, which explores the masticatory behavior and frequency/intensity of difficulty in chewing different types of foods. Results were submitted to normality tests, Chi-square, unpaired t-test and Mann-Whitney. A multiple linear regression model was used to evaluate which of the variables under study contributed to the variation in Percent Body Fat (α = 0.05). The results showed that OMES-e total score differed significantly between groups, that is, individuals with overweight showed more changes in oro-facial myofunctional aspects than normal-weight ones. Unilateral mastication was more frequent among females with overweight/obesity. They also showed greater difficulty on Habits and Fruit domains, reporting the need of adding sauce to the meal to facilitate swallowing and peeling and cutting fruit (apples) in small pieces in order to better chew them. OMES-e total score also showed a significant relationship with Percent Body Fat. Masticatory performance evaluated by chewing gum and bite force did not differ between groups. This study showed that adolescents with excess weight presented changes in masticatory behavior and greater difficulty in performing the masticatory function comparing to normal-weight ones.