Body Mass Index (PI12)
This indicator is the proportion of First Nations regular clients aged 18 and over who had their body mass index (BMI) classified within specified categories or not calculated within the previous 24 months.
It is reported here in 2 parts as the proportion of First Nations regular clients aged 18 and over who, within the previous 24 months, had:
- their BMI calculated
- their BMI calculated with a result of either:
- underweight
- normal
- overweight
- obese.
It is collected for males and females in age groups:
- 18–24
- 25–34
- 35–44
- 45–54
- 55–64
- 65 and over.
There have been changes to the specification of this indicator over time. For more information see Interpreting nKPI data.
Why weight is important
Being either underweight (for example, because of under-nutrition) or overweight or obese (where an abnormal or excessive amount of fat accumulates in the body) increases a person’s risk of poor physical health. Both are risk factors for future illness.
Data from the Australian Bureau of Statistics’ National Aboriginal and Torres Strait Islander Health Survey show that First Nations people aged 15 and over are less likely to be of normal weight than non-Indigenous Australians (AIHW and NIAA 2024). The proportion of First Nations people who are of normal weight has decreased over time.
At June 2025, 69% of (or around 166,000) First Nations regular clients aged 18 and over had their BMI calculated, 31% (74,100) had not (Figure 28).
The data visualisation below (Figure 28) shows, for each collection period from December 2021 to June 2025, the proportion of First Nations regular clients aged 18 and over who had their BMI calculated or not calculated within the previous 24 months. Select by either:
- organisation type
- remoteness
- state/territory
- age group/sex
to see data for that breakdown.
Data tables supporting this visualisation are available at Data.
Figure 28: Whether BMI was calculated by collection period
Overall, the proportion of First Nations regular clients aged 18 and over who had their BMI calculated within the previous 24 months generally increased between December 2022 and June 2025.
Notes
- In December 2021, specifications changed for this indicator and data from that point on cannot be compared with previous periods for all categories, age groups or the total. For more information see Interpreting nKPI data.
- A break is included to separate out the periods most affected by voluntary reporting and the peak of COVID-19 and associated emergency response measures. This break, however, is not a clean break as each indicator in the nKPI collection has an assigned time frame (a reference period) as part of its specification. For this indicator, which has a reference period of 24 months, data in collection periods for December 2022 (covering 1 January 2021 to 31 December 2022), June 2023 (covering 1 July 2021 to 30 June 2023) and December 2023 (covering 1 January 2022 to 31 December 2023) still overlap with the peak of COVID-19 and associated emergency response measures. For more information see Comparisons over time .
- The linear trend lines provide a general impression of the direction of the data. Caution should be taken interpreting trends with less than 5 data points. See also Figure 20 for trends for selected data.
- For more information, including on interpreting changes over time, see Technical notes.
Of those with their BMI calculated:
- 25% (or around 42,200) were overweight
- 25% (or around 42,100) were of normal weight
- 44% (or around 72,600) were obese
- 6% (or around 9,400) were underweight (Figure 29).
The data visualisation below (Figure 29) shows, for each collection period from December 2021 to June 2025, the proportion of First Nations regular clients aged 18 and over who had their BMI calculated within the previous 24 months by BMI result. Select by either:
- organisation type
- remoteness
- state/territory
- age group/sex
to see data for that breakdown.
Data tables supporting this visualisation are available at Data.
Figure 29: BMI result by collection period
Overall, the proportion of First Nations regular clients aged 18 and over who had their BMI calculated within the previous 24 months who had a normal weight generally increased between December 2022 and June 2025.
Notes
- In December 2021, specifications changed for this indicator and data from that point on cannot be compared with previous periods for all categories, age groups or the total. For more information see Interpreting nKPI data.
- Proportions are calculated using the denominator of First Nations regular clients with BMI calculated.
- A break is included to separate out the periods most affected by voluntary reporting and the peak of COVID-19 and associated emergency response measures. This break, however, is not a clean break as each indicator in the nKPI collection has an assigned time frame (a reference period) as part of its specification. For this indicator, which has a reference period of 24 months, data in collection periods for December 2022 (covering 1 January 2021 to 31 December 2022), June 2023 (covering 1 July 2021 to 30 June 2023) and December 2023 (covering 1 January 2022 to 31 December 2023) still overlap with the peak of COVID-19 and associated emergency response measures. For more information see Comparisons over time.
- The linear trend lines provide a general impression of the direction of the data. Caution should be taken interpreting trends with less than 5 data points. See also Figure 20 for trends for selected data.
- For more information, including on interpreting changes over time, see Technical notes.
Reference
Australian Institute of Health and Welfare and National Indigenous Australians Agency (2024) Measure 2.22 Overweight and obesity, Aboriginal and Torres Strait Islander Health Performance Framework website, AIHW, Australian Government, accessed 17 October 2025.