Being overweight or obese increases a person's risk of developing long-term health conditions such as cardiovascular disease, high blood pressure and Type 2 diabetes, while being underweight can also be a health risk factor for some people.
- In 2017-18, two thirds (67.0%) of Australian adults were overweight or obese (12.5 million people), an increase from 63.4% in 2014-15.
- This change was driven by the increase in the proportion of adults categorised as obese, which increased from 27.9% to 31.3%
- There was a large increase for those aged 18-24 years, with 38.9% overweight or obese in 2014-15 compared with 46.0% in 2017-18.
- In 2017-18, a greater proportion of men aged 18 years and over were overweight or obese than women (74.5% and 59.7% respectively).
- Almost one quarter (24.9%) of children aged 5-17 years were overweight or obese in 2017-18 (17% overweight and 8.1% obese). The rates were similar for boys and girls and this has remained stable over the previous ten years.
Body Mass Index (BMI) is a commonly used measure for defining whether a person is underweight, normal weight, overweight or obese. In the National Health Survey, respondents’ height and weight were measured to determine their BMI score. In the 2017-18 NHS, respondents were also asked to self report their height and weight.
In 2017-18, 33.8% of respondents aged 18 years and over did not have their height and or weight measured. For these people, height and weight were imputed using a range of information including their self reported height and weight. For more information see Appendix 2: Physical measurements in the 2017-18 National Health Survey.
Another method used to measure whether a person is a healthy weight or not is waist circumference. See Waist circumference for more information.
In 2017-18, two thirds (67.0%) of Australians 18 years and over were overweight or obese. Slightly more than a third (35.6%) were overweight and slightly less than a third were obese (31.3%). Just under one third (31.7%) were within the healthy weight range and one percent (1.3%) were underweight.
Since 2014-15, the proportion of adults aged 18 years and over who were overweight or obese increased from 63.4% to 67.0%. This change was driven by the increase in the proportion of adults categorised as obese, which increased from 27.9% to 31.3%. Since 1995, the proportion of adults aged 18 years and over who were overweight or obese increased from 56.2% to 67.0%, which was also associated with an increase in the proportion of people who were obese, which increased from 18.7% in 1995 to 31.3% in 2017-18. The proportion of adults who were overweight remained steady throughout this time.
In 2017-18, a greater proportion of men aged 18 years and over were overweight or obese than women (74.5% and 59.7% respectively). This difference was greatest in the overweight category, with 42.0% of men compared with 29.6% of women). The proportion of men who were in the obese category was also higher than for women but the gap was much narrower (32.5% compared with 30.2%). Since 2014-15, the proportion of both men and women in the obese category increased. For men this changed from 28.4% to 32.5% and for women the increase was from 27.4% to 30.2%. The proportion of men and women in the overweight category has remained constant since 2014-15.
In 2017-18, the proportion of adults aged 18 years and over who were overweight or obese in general increased with age. Less than half of those aged 18-24 years (46.0%) were overweight or obese. By age 35-44 years, this had increased to 68.7% and by the age of 65-74 years, the proportion had increased to almost four out of five (78.2%). However, there was a large increase for those aged 18-24 years, with 38.9% overweight or obese in 2014-15 compared with 46.0% in 2017-18.
Persons aged 18 years and over - proportion of overweight or obese, 1995 to 2014-15
In 2017-18, the proportion of adults aged 18 years and over who were overweight or obese increased with relative disadvantage. Seven in ten (71.8%) adults living in the areas of most disadvantage (first quintile) were overweight or obese in comparison to six in ten (62.6%) in the least disadvantaged (fifth quintile). This pattern remained relatively constant since 2014-15.
- A lower Index of Disadvantage quintile (e.g. the first quintile) indicates relatively greater disadvantage and a lack of advantage in general. A higher Index of Disadvantage (e.g. the fifth quintile) indicates a relative lack of disadvantage and greater advantage in general. See Index of Relative Socio-Economic Disadvantage in the Glossary.
In 2017-18, adults aged 18 years and over living in Inner Regional, and Outer Regional and Remote Australia were more likely to be overweight or obese than those living in Major Cities (72.4% and 72.2% compared with 65.0% respectively). Again, this pattern was consistent with the results from 2014-15 (Inner Regional Australia: 69.2% and Outer Region and Remote Australia: 69.2%, Major Cities: 61.1%,).
In 2017-18, the states which saw increases in the proportion of adults aged 18 years and over that were overweight or obese were Victoria (increased from 63.3% to 68.3%), South Australia (increased from 65.8% to 69.7%), Western Australia (increased 60.3% to 66.7%) and Tasmania (increased from 67.5% to 70.9%).