Two studies, in 1995 and 2000-02, were compared to assess changes in waist circumference in adolescents. Between the two time periods, waist circumference increased significantly in males at 13 years and in females at 14 years. Significant changes in waist circumference were observed during the study period; the rates of change were 0.53 and 0.86 cm/y in boys and 0.67 and 0.87 cm/y in girls. Future morbidity in adolescents may be affected due to accumulation of excess central fat.