Obesity is prevalent in the developed world. Data from the National Health and Nutrition Examination Survey (NHANES) 1988-1994 illustrate an obesity prevalence rate of 13.7% in the 6-11 age group and 11.5% in the 12-17 age group in the United States (11
). Also, the NHANES 2003-2006 has reported an obesity prevalence rate of 16.3% in the 2-19 age group (12
). In Europe, the highest obesity prevalence rates in school-aged children have been estimated in Spain and Portugal, while the lowest rates have been reported from Slovakia, France, Switzerland, and Iceland (13
Various reports in Turkish children and adolescents indicate that the prevalence of overweight and obesity may change by regions, however, the overall figures are lower as compared to many European countries and to the US (14
). In our study, the overweight prevalence rate was 8.3% (7.1% in the 11-14 age group and 9.7% in the 15-18 age group) and the obesity prevalence rate was 7.7% (5.9% in the 11-14 age group and 9.6% in the 15-18 age group). These results were comparable to other Turkish studies but lower than those reported for European countries and the United States.
Obesity and sedentary life style are closely related. In this study, 20.9% of the adolescents reported using computer for more than 2 hours/day. Similar to other published studies, boys spent more time than girls using computer (19
). Computer use was more prevalent in obese and overweight children. In this study, nearly half (52.4%) of the adolescents reported watching 2 or more hours of TV per day. The proportion of obese and overweight adolescents watching TV for more than 2 hours/day was higher as compared to normal-weight ones. A study by Ozmert et al (21
) reported similar results. Children with a BMI z-score >2 SD watched TV for longer periods than those with BMI z-scores < -2 SD.
Decreased physical activity is a serious risk factor for obesity (22
). In our study, more than 50% of the adolescents did not participate in any physical activity; 30% of the adolescents reported performing some regular activity. Boys declared more regular activity than girls. These results are similar to data published by Agazzi et al (20
). Adolescents with normal body weight reported more regular physical activity compared to their overweight and obese counterparts.
Having overweight parents has been shown to be a strong determinant of childhood obesity (24
). A study by Burke et al (25
) demonstrated the associations between child BMI and parental BMI. In this study, obesity in fathers was associated with a four-fold increase in the risk of obesity at the age of 18 years in both sons and daughters with an independent eight-fold increase in the risk for daughters if mothers were obese. In our study, 56% of the obese adolescents had an obese family member. The mean BMI of the adolescents increased as the parental BMI increased. In another study including 3306 children aged 5-7 years and their parents, the BMI of the children was found to be significantly correlated with the parental BMI. The children’s BMI showed closer associations with maternal than with paternal BMI (26
). In the present study, maternal obesity rate was highest in the study population. This may be due to mothers having a greater influence on their children’s nutrition in our society. Further prospective and comprehensive studies are needed on this topic.
In conclusion, the obesity prevalence among Turkish adolescents in the city of Ankara is relatively low as compared to many European countries and to the US. Computer use and TV viewing as well as physical activity and family factors are important risk factors for obesity in Turkish adolescents. Healthy nutrition and regular physical activity should be promoted to prevent obesity.