The association between self-reported physical activity levels and patterns and BMI of urban South African young adult women

Abstract

Background: Overweight and obesity are prevalent amongst urban South African women. Increasing levels of physical inactivity in these women are contributing to this pandemic, and these women are therefore at higher risk of developing non-communicable diseases. The aim of this study was to assess the self-reported physical activity levels and patterns of young adult urban South African women and determine if physical activity levels and patterns were associated with overweight and obesity. Methods: The Global Physical Activity Questionnaire was used to collect self-reported physical activity data in a cross-sectional study of 511 black females between 21-23 years of age from the Birth to Twenty plus cohort in Soweto, Johannesburg. Body mass index (BMI) was determined using standardised height and weight measurements. Participants who accumulated sufficient weekly physical activity according to the World Health Organisation (WHO) minimum recommended guidelines for physical activity were classified as WHO active and participants who did not meet these criteria were classified as WHO inactive.Results: The combined prevalence of overweight and obesity was 46.5% despite most (76.9%) of the women complying with the WHO minimum recommended guidelines for weekly physical activity. Walking for travel contributed most (33%) to weekly moderate-vigorous physical activity (MVPA), and less than a quarter (22%; n=109) of the participants reported any leisure time physical activity. The median sitting time was 6 hours a day and sitting time was not significantly different between the activity groups (WHO Active 360(260-480) min/day vs WHO Inactive 360(240-540) min/day; p=0.781)). We found no association between physical activity or sitting time, and BMI. Conclusion: This study shows that the majority of this group of young urban black females are classified as physically active according to the WHO minimum recommended guidelines for weekly physical activity, yet a large proportion are overweight and obese.