Background:Repeated overload by body weight in the adolescents affects the foot structure.Objective:This study aimed to evaluate plantar pressure distribution in adolescents with different body mass indices during gait and standing.Study design:This is a randomized, cross-sectional study.Methods:One hundred eighty-six adolescents between the ages of 8 and 15 years were included. The individuals were divided into groups according to body mass index (BMI). Plantar pressure distributions were examined during gait and standing. Surface areas, plantar pressures, forefoot-hindfoot load, surface amounts, and foot angles of the individuals were determined during gait and standing.Results:Significant differences were detected in left-right surfaces, maximum load quantities, average pressures, forefoot-hindfoot surface areas between static and dynamic plantar pressure distributions of underweight, normal, overweight, and obese adolescents (P < 001). Maximum, average pressure, right forefoot foot load, and foot angles increased in the obese group during standing as BMI increased; total surface areas, and loads in forefoot, hindfoot surface areas in right and left feet also increased in maximum and average pressures during gait (P < .05). No differences were detected between groups in foot angles during standing and gait (P > .05).Conclusions:This study show that increased BMI causes increased plantar pressures during gait and standing, and weight gain would cause problems in adolescents.