Overweight and obesity

Comprehensive, accurate and timely data are crucial for effective population health monitoring.

The increasing digitisation of health information means more detailed data are being collected. This expands the possibilities for analysing and reporting on a range of health risk factors and their relationships with different health outcomes. This in turn can be used to help guide implementation and strengthen efforts in preventive health, so that the health and wellbeing of all Australians can be improved at all stages – a vision of the National Preventive Health Strategy 2021–2030.

Although national health information collections continue to develop and improve, there are still gaps in data and instances where information needs to be brought together more efficiently for analysis.

Gaps and limitations

Current data used for analysis of overweight and obesity in the Australian population come from height, weight and waist circumference measurements collected in the Australian Bureau of Statistics (ABS) National Health Surveys.

These measurements are collected from respondents aged 2 years and over. As a result of their voluntary and sensitive nature, physical measurement collections have a relatively high rate of non–response.

Over the past decade, non-response rates for physical measurements have increased. In the 2011–12 Australian Health Survey, the non-response rate was 17% for respondents aged 2 and over. In the 2022 National Health Survey and the 2023 National Nutrition and Physical Activity Survey, the non-response rates increased to 41% for adults aged 18 and over and 57% for children aged 2–17, and 36% for adults and 45% for children, respectively. In recent years, the ABS has used a statistical method called ‘imputation’ to account for the high rate of non–response. For more information, see How imputation works.

However, despite this limitation, these health surveys still provide the most recent data on BMI and waist circumference from Australian households considered to be representative of most of the Australian population.

The use of pharmacological treatments for overweight and obesity has increased over the years. However, there is currently a lack of national data to capture and monitor the use of these treatments across Australia.

Other data gaps on health risk factors include:

• national data collected regularly on physical measurements, such as height, weight and waist circumference. This is important for population trend monitoring of overweight and obesity
• national comprehensive primary health care data collections, such as data from general practices, which are essential in the management and treatment of many risk factors and chronic conditions
• national data sources on non-medical treatment and management of overweight and obesity, such as weight-loss programs and lifestyle changes. This is important for population trend monitoring of the use of these strategies and could also provide insight into people’s experiences
• national datasets that link information on health risk factors, such as overweight and obesity, to other risk factors and chronic conditions. This will allow for analysis exploring how different risk factors affect health, providing key insights into the relationships between these different health determinants and the development of chronic diseases
• detailed information on priority population groups, including people with disability, culturally and linguistically diverse populations, refugee and LGBTQI+ populations
• measures of health system efficiency and cost-effectiveness of treatments for different conditions and risk factors like overweight and obesity.