Associations between active commuting to school, fat mass and lifestyle factors in adolescents: the Kiel Obesity Prevention Study (KOPS).

OBJECTIVE

To examine possible associations between active commuting (walking or cycling) to school, parameters of adiposity and lifestyle factors in 14-year-old adolescents of the Kiel Obesity Prevention Study.

SUBJECTS

A total of 626 14-year-old adolescents.

METHODS

Measured body mass index (BMI), fat mass (FM), distance to school as well as self-reported modes and duration of commuting to school, time spent in structured and unstructured physical activities (PAs), media use, nutrition, alcohol consumption and smoking.

RESULTS

Parameters of adiposity did not differ between different commuting modes after stratifying by gender. Active commuters reported higher overall PA, which was caused by commuting activity and time spent in unstructured PA in girls and just by commuting activity in boys. In active commuters, 28.4% of overall PA was explained by commuting activity. Additionally, TV viewing was lower in active commuters. Compared to their inactively commuting counterparts, actively commuting boys were less likely to smoke. After controlling for potential confounders the interaction term 'active commuting by distance to school' and 'time spent in structured PA' were independent predictors of FM, whereas active commuting by itself showed no effect.

CONCLUSION

The present data suggest that active commuting to school per se does not affect FM or BMI until considering distance to school. Increasing walking or cycling distance results in decreasing FM. However, the everyday need to get to and from school may enhance adolescents' overall PA.