Walking and body mass index in a Portuguese sample of adults: a multilevel analysis

Physical inactivity is an important risk factor for many chronic diseases. The purpose of this study was to investigate the cross-sectional associations between walking and body mass index (BMI). This study comprised 9991 adults (5723 women), aged 37.8+/-9.5 years, from the 2004 Azorean Physical Activity and Health Study. Walking was assessed with the International Physical Activity Questionnaire, and expressed as minutes per week. BMI was calculated from self-reported weight and height. A series of multilevel linear regression models were fitted to assess regression coefficients and s.e. predicting BMI. Results show that, in both genders, and after adjustments for potential confounders, walking was not a significant predictor of BMI. Therefore, our analysis does not extend the findings of earlier studies as it shows no significant associations between walking and BMI, after adjustments for potential confounders. Nevertheless, among Azoreans walking should be encouraged, as walking has other health benefits, beyond controlling obesity.