Effect of activity and television viewing on BMI z-score in early adolescents in Turkey

Abstract

television, computer and other causes of increased inactivity are reported to be among the major causes of obesity. This cross-sectional study was aimed to evaluate the effect of television viewing and other daily activities on body mass index (BMI) z-score of early adolescents. a total of 860 students and their parents (581) from different socioeconomic level schools were included. They were instructed to fill in a self-designed questionnaire. Weight and height were measured, and BMI z-scores were calculated. BMI z-score was higher in boys and in those attending high socioeconomic level schools. Children with a BMI z-score >2SD watched television (2.5 ± 0.9 h/day) longer than those with <-2SD (1.6 ± 0.8 h/day) (P=0.027). The three categories (<-2SD, -2SD-2SD, >2SD) differed significantly according to maternal (P<0.05) and paternal (P<0.005) BMI. Linear logistic regression analysis revealed that socioeconomic level, maternal BMI and paternal BMI are factors affecting BMI z-score significantly. genetic and/or family environment which may affect the nutrition and activity of adolescents seems to be the most important factor affecting their BMI z-score.