Overweight and obesity are associated with many noncommunicable diseases (NCDs), including cardiovascular diseases (CVD), type 2 diabetes (T2DM) and cancer, with a ranking of fourth as a risk factor for death.1-2 Projections are alarming in suggesting that overweight and obesity will affect over 4 billion people globally by 2035, comprising an increase in those affected from 38% of the world’s population in 2020 to over 50% by 2035.3
Cancer is the third leading cause of mortality and premature disability attributable to high body mass index (BMI) after cardiovascular disease (CVD) and T2DM.4 Globally, it is estimated that the age standardized mortality rate from cancer attributable to high BMI was 5.69 per 100,000 in 2019, accounting for 11.18 million DALYs. The estimated high BMI-related cancer cases accounted for 4.59% and 4.45% of all cancer-cause deaths and DALYs, respectively.5
Overweight and obesity are a major public health concern in Australia. In 2018, 8.4% of the total disease burden in Australia was due to overweight and obesity, making it the second leading risk factor contributing to disease burden after tobacco use. It was the leading risk factor for the non-fatal burden of disease, contributing 7.4% years lived with disability. Overweight (including obesity) is estimated to contribute to the burden of 30 diseases including 17 types of cancer.6-7
Charts
About this measure
Overweight and obesity are calculated using the Body Mass Index (BMI), a scale based on height and weight commonly used to define whether a person is underweight, normal weight, overweight or obese.8-9 BMI is calculated by dividing a person’s weight (in kilograms) by their height (in metres). Guidelines established by the World Health Organization8 and the National Health and Medical Research Council9 place adults aged 18 years and older into the following categories based on their BMI:
Table 1: Classifications of BMI for adults aged 18 years and over
BMI (kg/m2) | Classification |
Less than 18.5 | Underweight |
18.5 to less than 25 | Healthy weight |
25.0 to less than 30 | Overweight but not obese |
30.0 to less than 35 | Obese class I |
35.0 to less than 40 | Obese class II |
40.0 or more | Obese class III |
25 or more | Overweight or obese |
Where relevant, rates are age-standardised for this measure to account for differences in age structures over time. Age-standardisation has also been applied for comparisons between population groups, including those classified by Indigenous and non-Indigenous status, areas of residential remoteness, and areas by level of socioeconomic disadvantage.
Current status
In 2022, an estimated 13 million Australian adults (65.8% of the adult population) aged 18 years and over were overweight or obese; 34.0% were overweight but not obese, and 31.7% were obese. Men had higher rates of overweight and obesity than women (with 71.2% vs 60.5% affected).10 This can be attributed mainly to a higher proportion of males being overweight compared with females (38.6% compared with 29.6%), although with obesity rates only marginally higher in males (at 32.5% vs 30.9%).10
The prevalence of adults being overweight or obese increases with age, peaking at 55-64 years for females (69.5%) and 65-74 years for males (81.4%). Less than half of people aged 18-24 years (42.1%) were overweight or obese. This prevalence was higher at 66.7% for peoples aged 35-44 years and 75.1% for ages 65-74 years. Overall, 14.3% of adults aged 18–24 years were obese, compared with 38.5% of adults aged 65–74 years.10
The proportion of overweight and obese people was significantly higher for males than females across all age groups. The greatest difference by sex was in the age range of 35-44 years (74.8% compared to 58.3%, respectively).10
Morbidly obese (Severely obese)
In 2022, 12.7%. of Australian adults was reported to be morbidly obese (having a BMI score of 35 or more). Females tended more to be morbidly obese than males although the difference was small (13.5% compared with 11.8%).10
Remoteness and socioeconomic status (SES)
In 2022, the proportions of overweight or obese people among those living in Outer regional and Remote areas, excluding very remote areas, was 70.3%. which tended to be higher than for the Inner regional areas (69.3%) and Major cities (64.0%).10
There was the suggestion of a higher proportion of people living in the lowest SES areas being overweight or obese than for the highest SES areas (age standardised proportion of 65.9% compared with 62.8%).10
Trends
After adjusting for age differences over time, the proportion of the population recorded as overweight/obese increased from 57.1% in 1995 to 66.5% in 2017-18, and then decreased marginally to 65.8% in 2022. This change reflected an increase in levels of obesity, from 18.9% in 1995 to 30.8% in 2017-18 and 31.7% in 2022, with a reverse trend in the overweight proportion from 38.2% to 35.6% in 2017-18 and 34.0% in 2022, respectively.10-13
From 1995 to 2017-18, the proportion of overweight or obese men increased from 52.0% to 74.5%, compared with a corresponding increase from 37.0% to 59.7% in women. These rates then tended to stabilize at 60.5% in women and to decrease to 71.2% in men in 2022.10-13
About the data
This measure indicates the proportions of people who were overweight or obese.
Numerator: Number of persons aged 18 years and over who were overweight or obese (i.e., BMI score of 25 or greater).
Denominator: Number of persons aged 18 years and over having their height and weight measured
BMI is calculated by dividing a person’s weight (in kilograms) by their height (in metres). Guidelines established by the World Health Organization8 and the National Health and Medical Research Council9 place adults aged 18 years and older into the following categories based on their BMI:
Table 1: Classifications of BMI for adults aged 18 years and over
BMI (kg/m2) | Classification |
Less than 18.5 | Underweight |
18.5 to less than 25 | Healthy weight |
25.0 to less than 30 | Overweight but not obese |
30.0 to less than 35 | Obese class I |
35.0 to less than 40 | Obese class II |
40.0 or more | Obese class III |
25 or more | Overweight or obese |
Methodology
Remoteness
The Australian Statistical Geography Standard (ASGS) Edition 3 was used to allocate participants to a remoteness area based on their area of usual residence.15 Note that earlier data used the ASGS 2016 & ASGS 2011.
Socioeconomic status
The 2016 Socio-Economic Indexes for Areas (SEIFA) Index for Relative Socio-Economic Disadvantage was used to allocate participants to a SEIFA quintile based on their usual residence.16 For 2011-2012 and 2014-2015 data, the 2011 IRSD was used. Data for socioeconomic status and remoteness are available for persons in general for 2022 (note: not yet available by sex).
Data caveats
The calculation of BMI is based on measured height and weight data collected from the Australian Bureau Statistics 1995 National Nutrition Survey, 2011-12 Australian Health Survey – Core Content, and 2007-08, 2014-15, 2017-18 and 2022 National Health Survey.
In 2022, estimates of obesity class II and III in females aged 18-24 years had a relative standard error (RSE) of 25% to 50% and greater than 50%, respectively and should be used with caution. A RSE value of 50% has been applied to calculate the RSE for morbidly obese classification in this group since it has not been reported in public publication. Hence, this RSE should be considered too unreliable for general use.
Non-response rates14
- Physical measurements have a relatively high rate of non-response due to their voluntary and sensitive nature. To correct for the high rate of non-response, imputation of values for those that did not have measurements collected was used to achieve estimates of physical measurements for the whole population.
- Non-response rates for physical measurements were higher in 2022 than in the 2017–18 NHS (which in turn were higher than the 2014–15 NHS). The non-response for BMI for adults in 2022 was 40.8%, compared with 33.8% in 2017–18 and 26.8% in 2014–15.
- The higher non-response rates in 2022 could in part be due to the trend of declining participation in physical measures, however it is considered that the COVID-19 pandemic would also have had an effect. The procedures for collecting physical measurements in the 2022 NHS were adapted to include increased hygiene and social distancing measures, and respondents were required to take their own measurements (rather than have ABS Interviewers taking measurements).
Self-reported height and weight14
- In addition to the voluntary measured items, respondents in the 2022 NHS were also asked to self-report their height and weight measurements. This provides valuable information about height and weight that can be used in assisting in the imputation for those with missing values.
Imputation
- In the 2022, 2017–18 and 2014–15 NHS, missing values were imputed using the 'hot decking' imputation method.
- Physical measurement data (BMI, waist circumference) that includes imputed values are of suitable quality for comparisons to 2017–18 and 2014–15 NHS. For comparisons to earlier years, the Australian Bureau of Statistics (ABS) recommends using proportion comparisons only as imputation was not used on the physical measurement data prior to 2014–15 NHS.
- The below table presents the proportions of persons aged 18 years and over who did not have their height and/or weight measured across the survey years.For these respondents, imputation was used.
Survey Year | Height and/or weight not measured (%) |
1995 | N/A |
2007-08 | 28.6 |
2011-12 | 15.8 |
2012-13 | 15.0 |
2014-15 | 26.8 |
2017-18 | 33.8 |
2022 | 40.8 |
Data sources
ABS 2022, 2017-18, 2014-15, 2011-12 and 2007-08 National Health Survey
ABS 1995 National Nutrition Survey
ABS 2012-13, 2018-19 Australian Aboriginal and Torres Strait Islander Health Survey – Core Content
OECD. Stat. Health Statistics (database). Non-medical determinants of health. OECD; 2020. https://stats.oecd.org/Index.aspx?QueryId=30128
References
Data:
Australian Bureau of Statistics 2023. Waist Circumference and BMI. Accessed May 2024;
Australian Bureau of Statistics 2018. Cat no. 4364.0.55.001. Overweight and obesity in 2017-2018. Accessed May 2024; https://www.abs.gov.au/statistics/health/health-conditions-and-risks/overweight-and-obesity/2017-18#data-downloads
Australian Bureau of Statistics. 4364.00.55.001 – National Health Survey: First Results 2017-18. Canberra: ABS; 2018. Accessed May 2024; https://www.abs.gov.au/statistics/health/health-conditions-and-risks/national-health-survey-first-results/latest-release
Australian Institute of Health and Welfare. Web report. Cat. no: PHE 251. Overweight and Obesity: an interactive insight 2020. Accessed May 2024; https://www.aihw.gov.au/reports/overweight-obesity/overweight-and-obesity-an-interactive-insight/data
Australian Bureau of Statistics. 4715.0 – National Aboriginal and Torres Strait Islander Health Survey, 2018-19. Canberra: ABS; 2019. Accessed May 2024; https://www.abs.gov.au/statistics/people/aboriginal-and-torres-strait-islander-peoples/national-aboriginal-and-torres-strait-islander-health-survey/2018-19
Organisation for Economic Co-operation and Development (OECD) 2023. OECD.Stat. Paris. Accessed May 2024; https://stats.oecd.org/index.aspx?DataSetCode=HEALTH_STAT#
Policy:
National Health and Medical Research Council 2013. Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults, Adolescents and Children in Australia. NHMRC: Canberra; 2013; Accessed May 2024; https://nhmrc.gov.au/about-us/publications/clinical-practice-guidelines-management-overweight-and-obesity
Commonwealth of Australia 2022. The National Obesity Strategy 2022-2032. Health Ministers Meeting. Accessed May 2024; https://www.health.gov.au/resources/publications/national-obesity-strategy-2022-2032?language=en
References
- WHO 2022. Obesity causes cancer and is a major determinant of disability and death, warns new WHO report May 2022. Accessed May 2024; https://www.who.int/europe/news/item/03-05-2022-obesity-causes-cancer-and-is-major-determinant-of-disability-and-death--warns-new-who-report
- Lin X, Li H. Obesity: epidemiology, pathophysiology, and therapeutics. Front Endocrinol. 2021:12:706978.
- World Obesity Federation, World Obesity Atlas 2023. Accessed May 2024; https://data.worldobesity.org/publications/?cat=19
- Dai H, Alsalhe TA, Chalghaf N, et al. The global burden of disease attributable to high body mass index in 195 countries and territories, 1990-2017: an analysis of the Global Burden of Disease Study. PLoS Med. (2020) 17:e1003198.
- Zhi X, Kuang XH, Liu K, et al. The global burden and temporal trend of cancer attributable to high body mass index: Estimates from the Global Burden of Disease Study 2019. Front Nutr. 2022 Jul 26; 9:918330.
- Australian Institute of Health and Welfare 2021. Australian Burden of Disease Study 2018: Interactive data on risk factor burden. Web report. Accessed May 2024; https://www.aihw.gov.au/reports/burden-of-disease/abds-2018-interactive-data-risk-factors/contents/overweight-including-obesity
- Australian Institute of Health and Welfare 2021. Australian Burden of Disease Study: Impact and causes of illness and death in Australia 2018 - Summary report. Accessed May 2024; https://www.aihw.gov.au/reports/burden-of-disease/abds-2018-summary/summary.
- World Health Organization. A healthy lifestyle - WHO recommendations. Geneva: WHO; 2016. Accessed May 2024; https://www.who.int/europe/news-room/fact-sheets/item/a-healthy-lifestyle---who-recommendations
- National Health and Medical Research Council. Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults, Adolescents and Children in Australia. Canberra: NHMRC; 2013. Accessed May 2024; https://www.nhmrc.gov.au/about-us/publications/clinical-practice-guidelines-management-overweight-and-obesity
- Australian Bureau of Statistics 2023. Waist Circumference and BMI. Accessed May 2024; https://www.abs.gov.au/statistics/health/health-conditions-and-risks/waist-circumference-and-bmi/latest-release
- Australian Bureau of Statistics 2018. Cat no. 4364.0.55.001 - National Health Survey, 2017-18. Canberra: ABS; 2018. Accessed May 2024; https://www.abs.gov.au/statistics/health/health-conditions-and-risks/national-health-survey/2017-18
- Australian Bureau of Statistics 2008. Overweight and Obesity in Adults, Australia, 2004-05. Accessed May 2024; https://www.abs.gov.au/ausstats/abs@.nsf/Latestproducts/4719.0Main%20Features22004-05%3Fopendocument%26tabname=Summary%26prodno=4719.0%26issue=2004-05%26num=%26view=#:~:text=The%20proportion%20of%20men%20classified,45%25%20in%202004%2D05.
- Australian Institute of Health and Welfare 2023. Web report. Cat. no: PHE 251. Overweight and Obesity. Accessed May 2024; https://www.aihw.gov.au/reports/overweight-obesity/overweight-and-obesity/contents/about
- Australian Bureau of Statistics 2023. National Health Survey methodology. Accessed May 2024; https://www.abs.gov.au/methodologies/national-health-survey-methodology/2022#summary-of-content-changes
- Australian Bureau of Statistics 2023. Remoteness Areas. Accessed May 2024; https://www.abs.gov.au/statistics/standards/australian-statistical-geography-standard-asgs-edition-3/jul2021-jun2026/remoteness-structure/remoteness-areas
- Australian Bureau of Statistics 2023. Socioeconomic Indexes for areas (SEIFA) 2016. Accessed May 2024; https://www.abs.gov.au/ausstats/abs@.nsf/mf/2033.0.55.001