Trends in body mass index and obesity prevalence in Western Australian adults, 2002 to 2015.

ISSUE ADDRESSED: Continued increases in overweight and obesity across most parts of the world in recent decades have seen maintaining or reaching a healthy weight become a major public health priority. This study reports on body mass index (BMI) and obesity prevalence trends in Western Australian adults between 2002 and 2015.

METHODS: Self-reported height and weight were collected from Western Australian adults (16+ years) via 81 867 computer-assisted telephone interviews conducted between 2002 and 2015 as part of the WA Health and Wellbeing Surveillance System. Linear and quadratic trends in annual mean BMI and obesity prevalence estimates were generated from self-report data. These trends were subject to sequential sum of squares analysis to examine whether annual increases in mean BMI and obesity prevalence estimates diminished or were maintained over the 2002 to 2015 period.

RESULTS: The analyses showed a preference for a quadratic model (with plots suggesting diminishing increases between 2002 and 2015) in mean BMI for males, 25- to 64-year-olds and across all adults, and in obesity prevalence estimates across all adults.

CONCLUSIONS: The results suggest the rate at which mean BMI and obesity prevalence are increasing may be slowing overall and within specific groups in WA. SO WHAT?: The findings are potentially a positive news story for health in Western Australia. Even so, 2-thirds of the population are overweight or obese and there remains a strong need for sustained obesity prevention action.