Time trends

The interactive graphs below allow you to explore how the prevalence of overweight and obesity has changed over time in different populations.

Children and adolescents

Information dating back to 1995 is available for children aged 5–17. It shows that the prevalence of overweight and obesity rose from 20% in 1995 to 25% in 2007–08. Then, from 2007–08 to 2017–18, the prevalence of overweight and obesity remained relatively stable, with no significant increase or decrease.

Similarly, the prevalence of obesity increased from 4.9% in 1995 to 7.5% in 2007–08 then remained relatively stable to 2017 –18 (8.1%). Rates of overweight but not obese children rose between 1995 and 2014–15, then declined to 2011–12 levels for 2017–18. However, the decline did not result in less overweight and obese children overall, but instead resulted in some children moving from the overweight category to the obese category.

Adults

After adjusting for different population age structures over time, the prevalence of overweight and obesity among Australians aged 18 and over increased from 57% in 1995 to 67% in 2017–18. Over this time period the prevalence of overweight but not obese did not change substantially (from 38% to 36%), but the prevalence of obesity increased from 1 in 5 (19%) to 1 in 3 (31%).

The distribution of BMI shifted towards higher BMIs from 1995 to 2017–18, due to an increase in obesity in the population over time. 

Birth cohort

The prevalence of overweight and obesity differs by birth cohort. A birth cohort can be defined as a group of people born in the same year or years.

At ages 10–13 and 14–17, children and adolescents born most recently were significantly more likely to be overweight or obese than those born 20 years earlier. At age 10–13, 31% of children and adolescents born from 2002–2005 were overweight or obese compared with 24% of those born from 1982–1985. At age 14–17, 30% of adolescents born from 1998–2001 were overweight or obese compared with 19% of adolescents born from 1978–1981. There were no statistically significant differences for overweight and obesity at ages 2–5 and 6–9.

In all but one of the age groups assessed in a recent report by the AIHW Overweight and obesity in Australia: a birth cohort analysis, adults born most recently were significantly more likely to be obese than those born 20 years earlier. The largest relative difference across cohorts was at age 18–21; 15% of those born from 1994–1997 were obese at age 18–21, almost double the proportion of those born from 1974–1977 (8%) at the same age.

For more information, see A picture of overweight and obesity in Australia and Overweight and obesity in Australia: a birth cohort analysis.

International comparisons

In 2017, Australia had the 8th highest proportion (64%) of overweight or obese adults aged 15 and over among 23 OECD member countries with data available for measured BMI, based on data from that year or the latest available year (OECD 2018).

Chile had the highest overall proportion of overweight or obese (74%), and overweight but not obese persons (40%), while Japan had the lowest (25% and 21%, respectively). The United States had the highest proportion of obese adults, at 4 in 10 (40%) people aged 15 and over.

Australia is one among a number of OECD member countries in which the prevalence of overweight and obesity has increased over recent decades, and in Australia as well as most other countries, this increase has been driven by the increased proportion of people who are obese (OECD 2018). This upward trend is expected to continue—OECD projections show a steady increase in obesity rates until at least 2030 (OECD 2017).

There has been an increase in the proportion of obese people (aged 15 and over) across OECD member countries over the past 2 decades—from an average of 19% in 2000 to 28% in 2017.

References

AIHW 2017. Overweight and obesity in Australia: a birth cohort analysis. AIHW cat. no. PHE 215. Canberra: AIHW.

ABS (Australian Bureau of Statistics) 2009. National Health Survey: summary of results, 2007–08 (reissue).  ABS cat. no. 4364.0. Canberra: ABS.

ABS 2010. Information paper: National Health Survey, basic and expanded CURF, 2007–08, expanded confidentialised unit record file, DataLab. ABS cat. no. 4324.0. Canberra: ABS. Findings based on AIHW analysis of ABS microdata.

ABS 2013a. Australian Health Survey: updated results, 2011–12. ABS cat no. 4364.0.55.003. Canberra: ABS.

ABS 2013b. Microdata: National Nutrition Survey, 1995, basic confidentialised unit record file, DataLab. ABS cat. no. 4807.0.30.001. Canberra: ABS. Findings based on AIHW analysis of ABS microdata.

ABS 2014. Microdata: Australian Health Survey, core content—risk factors and selected health conditions, 2011–12, expanded confidentialised unit record file, DataLab. ABS cat. no. 4324.0.55.003. Canberra: ABS. Findings based on AIHW analysis of ABS microdata.

ABS 2015. National Health Survey: first results, 2014–15. ABS cat no. 4364.0.55.001. Canberra: ABS.

ABS 2016. Microdata: National Health Survey, 2014–15, expanded confidentialised unit record file, DataLab. ABS cat. no. 4324.0.55.001. Canberra: ABS. Findings based on AIHW analysis of ABS microdata.

ABS 2019. Microdata: National Health Survey 2017–18. ABS cat. no. 4324.0.55.001. Canberra: ABS. AIHW customised data request

OECD (Organisation for Economic Co-operation and Development) 2018. OECD health statistics 2018. Paris: OECD Publishing. Viewed 11 January 2019.

OECD 2017. Obesity update 2017. Paris: OECD Publishing.