Australian Award - Population Trends in Adults Physical Activity, Sedentary Behaviour and Overweight and Obesity

Abstract

Introduction: Levels of both physical activity (PA) and sedentary behavior (SB) have shown to be important to reduce the risk of many chronic diseases including weight gain. This study examined trends in the prevalence of PA and SB, and trends in overweight and obesity (O/O) in groups engaging in different amounts of PA and SB. METHODS: Data was obtained from a telephone survey of Central Queensland adults conducted annually from 2002 to 2008. A total of 8656 adults participated in seven cross-sectional surveys and were pooled for analyses. PA was assessed using the Active Australia Questionnaire, participants were classified as sufficiently active (SPA) or insufficiently active (IPA). SB was assessed using two separate items; time spent watching TV and working in front of a computer in the last week. The combined total of SB was dichotomized at 21 hours/week, into Low SB (LSB) and High SB (HSB). Data were pooled and four mutually exclusive activity groups were created: LSB/SPA, LSB/IPA, HSB/SPA and HSB/IPA. Logistic regression was used to examine likelihood of O/O in each activity group (pooled analysis), change in the prevalence of each activity group over time (trend analysis), and change in the prevalence of O/O over time in each group (trend analysis). All analyses were stratified by gender and adjusted for age, gender, education, employment status and smoking status. RESULTS: Compared to those who engaged in LSB/SPA, those who engaged in HSB/SPA (Men OR=1.37; Women OR=1.23) and HSB/IPA (Men OR=1.42; Women OR=1.83) were significantly more likely to be classified as O/O. The proportion of men and women engaging in LSB/IPA decreased over time (OR=0.96, 0.95 respectively), the proportion of both genders engaging in HSB/SPA increased over time (OR=1.05, 1.04 respectively). For men, the prevalence of O/O did not significantly change over time in any activity group. For women, the prevalence of O/O changed significantly over time in the HSB/IPA (OR=1.10) group only. CONCLUSION: These findings suggest that although the prevalence of SPA appears to be gradually increasing, it is occurring in conjunction with an increased prevalence of HSB. Increasing proportions of O/O were observed only in women in the HSB/IPA group, highlighting the need to simultaneously increase PA and reduce SB to reduce the risk of O/O in this group.