Prevalences of overweight and obesity and their association with physical activity pattern among Iranian adolescents aged 12-17 years.

OBJECTIVE: The objective of the present study was to investigate the prevalences of overweight and obesity and their association with physical activity pattern among adolescents in northern Iran.

DESIGN: A cross-sectional study.

SETTING: Babol, northern Iran.

SUBJECTS: A representative sample of 1200 adolescents aged 12-17 years was recruited. All selected adolescents were interviewed, their leisure-time and sport physical activities were collected by a standard Baecke questionnaire and their height and weight were measured by standard methods. The diagnosis of overweight and obesity was determined by comparing BMI values with the BMI index for age and sex percentiles set by the US Centers for Disease Control and Prevention in 2000.

RESULTS: The prevalences of overweight and obesity were 15.1 % and 8.3 %, respectively. The proportion of obesity was significantly higher in boys than in girls (10.2 % v. 6.5 %, P = 0.028). Overall, the levels of high, moderate and low leisure-time physical activity were 2.9 %, 79.4 % and 17.7 %, respectively. The corresponding levels of high, moderate and low sport physical activity were 17.4 %, 75.2 % and 7.4 %. The levels of leisure-time and sport physical activities were significantly higher among the boys than the girls (P < 0.001). There was also a significant association of studying in private schools and playing computer games with overweight/obesity (P < 0.001). Moderate leisure-time physical activity was unexpectedly associated with a greater risk of overweight/obesity compared with the low level (P = 0.002).

CONCLUSIONS: The findings indicate a high prevalence of overweight/obesity in these Iranian adolescents, particularly the boys. The influence of physical activity and diet on overweight/obesity requires further prospective studies.