Part 1 of this two-part post provided a global and broad Australian perspective on the pandemic of overweight and obesity. This part sets out the position for indigenous Australians and argues that this pandemic is a significant part of the health gap between indigenous and non-indigenous Australians and that the way forward must involve interventions to address the problem at childhood and adolescent stages.
What needs to be recognised up front is that the well-documented gap between the health of indigenous Australians and that of non-indigenous Australians is part of a global picture for indigenous and tribal peoples. Globally there are more than 300 million indigenous and tribal peoples living in approximately 90 countries. The most extensive global survey of the health status of these peoples surveyed 23 of these countries, covering 128 indigenous and tribal groups. The survey covered Australia, New Zealand, Canada, USA, Northern Europe, Russia, South America and parts of Asia. The survey found that indigenous peoples everywhere experienced poorer health and social circumstances than the wider population and that this deprivation is regardless of the relative wealth of the country. This would indicate that there is a common underlying experience and history of loss of territorial possession and cultural identity and social exclusion.
The estimated gap in life expectancy between indigenous and non-indigenous Australians is about 12 years for males and 10 years for females. This in fact understates the actual health gap because it does not measure the relative morbidity during the period of life. Indigenous Australians have a greater overall burden of disease and both a lower life expectancy and a lower level of health during life.
Chronic diseases were responsible for 64 per cent of this burden. The leading causes of total health loss were mental and substance disorders (19 per cent), injuries, including suicide (15 per cent), cardiovascular disease (12 per cent), cancer (9 per cent) and respiratory diseases (8 per cent). The total burden of disease was 2.3 times that of non-indigenous Australians, with chronic diseases responsible for 70 per cent of the disease burden gap between indigenous and non-indigenous Australians.
The disease burden was substantially higher for people living in remote and very remote areas but was also significantly higher for all indigenous Australians relative to non-indigenous Australians. Those living in areas of high socio-economic disadvantage had 2.4 times the burden of those living in areas with the lowest socio-economic disadvantage.
In order to assess policy responses it is necessary to seek to link the gap in life expectancy and the additional health burden to risk factors that are capable of being addressed. This has been assessed with the result being that the leading contributors in 2011 were tobacco use (12 per cent), alcohol use (8 per cent), overweight and obesity (8 per cent), physical inactivity (6 per cent), high blood pressure (5 per cent) and high blood sugar (5 per cent), with a range of dietary factors contributing a combined 10 per cent. The Australian Institute of Health and Welfare (AIHW) did not explicitly take account of socioeconomic disadvantage as a risk factor but it clearly is a significant contributor and underpins many of the risk factors.
The combination of the linked risk factors of overweight and obesity, poor diet and inactivity is the largest group of risk factors. Obesity rates for each age group were significantly higher than for the same age groups in the non-indigenous population. After adjusting for differences in age structure between the two populations, indigenous people were 1.5 times as likely as non-indigenous Australians to be obese (rate ratio of 1.4 for males and 1.7 for females).
Overweight and obesity increases a person’s risk of developing cardiovascular disease, high blood pressure, type 2 diabetes, chronic kidney disease and certain types of cancer. High body mass contributes to 64 per cent of the burden of diabetes for indigenous Australians, 46 per cent of chronic kidney disease and 39 per cent of coronary heart disease burden.
The excess health burden of overweight and obesity in the indigenous population reduces average life expectancy by between one and three years, accounting for between 9 per cent and 17 per cent of the total life expectancy gap, while physical inactivity contributed 12 per cent and a diet inadequate in fruit and vegetables contributed a further 5 per cent.
Indigenous adults were less likely than non-Indigenous Australians to have a sufficient level of physical activity (a 0.8 risk rate) and more likely to be inactive (a risk rate of 1.3), with relative inactivity increasing with age. Low levels of physical inactivity were reported in nearly 60 per cent of indigenous people 18 and over in non-remote areas in 2012-13.
Indigenous Australians are twice as likely to report having less than the desired level of daily fruit intake (two portions a day) and seven times as likely to report having less than adequate level of daily vegetable intake (five portions), relative to non-Indigenous Australians.
Studies drawing on the longitudinal data demonstrate that the problem of overweight and obesity in the indigenous population starts in early childhood. Drawing on an ABS survey for 2012-13, the rate of overweight and obesity in indigenous children aged 2 to 4 was 22.4 per cent; 27.5 per cent for children 5 to 9; and 38.5 per cent for children 10 to 14. For indigenous people aged 15 and over 66 per cent were overweight (29 per cent) or obese (37 per cent).
However, it is important to not become solely focussed on health behaviours such as diet and physical activity. There is a complex set of interacting factors that include genetics, metabolism, behaviours, socioeconomic conditions, the physical and food environment and culture, all of which can influence overweight and obesity.
Studies have found that between one third and half of the health gap between indigenous Australians and non-indigenous Australians is associated with differences in socioeconomic status. Indicators of this disadvantage, relating to 2014-15, include the following:
- 36 per cent of indigenous Australians were living in households in the lowest income quintile compared to 17 per cent for non-Indigenous Australians;
- 21 per cent of indigenous Australians lived in overcrowded households, 3.8 times the rate for non-indigenous Australians, and around 26 per cent of indigenous Australian households were living in dwellings with major structural and health problems;
- only 29 per cent of indigenous Australians lived in homes owned or being purchased by household members, compared with 69 per cent for non-indigenous Australians;
- 35 per cent of indigenous Australians rented in social housing and 32 per cent were in private rental.
Diet is influenced by factors such as housing and housing condition, location, education, income and availability and cost of different types of food. The general view is that healthy foods are more expensive than energy dense/nutrient poor processed food and in lower socioeconomic and remote areas, healthy food is less available.
There is a compelling case for prioritising the high incidence of overweight and obesity of indigenous Australians, in particular with respect to indigenous children and adolescents. There is a national commitment to closing the gap in terms of life expectancy and the overall burden of disease between indigenous and non-indigenous Australians. Due to the specific circumstances, such as low socioeconomic position, poor diet, physical inactivity and poor and unhealthy housing impacting on many in the indigenous community, there is a high incidence of overweight and obesity in the indigenous community that contributes a significant part of the life expectancy and burden of disease gap.
It could be objected that there is a national problem for the population as a whole and hence there should be a national prevention program targeting the overall population. There are three responses to that objection:
- first, that tacking indigenous obesity as early as possible needs to be part of the tacking the gap national commitment;
- second, the specific circumstances and culture of the indigenous community requires its own targeted program which can be reinforced as and when broader initiatives are undertaken;
- third, that the most effective way of tacking the obesity problem is by prioritizing and targeting children and adolescents.
From the interventions to improve obesity in indigenous communities to date, which have been mainly in remote areas, the following broad lessons can be drawn that appear relevant to the design and implementation of interventions directed at improving the diet and health of indigenous Australians.
- The design needs to incorporate both supply side and demand side features: the demand side seeks to influence the perception of and demand for healthy food by providing education and training on nutrition and diet and the link to health and wellbeing while the supply side seeks to influence positively the supply of healthy food to the indigenous community.
- In remote communities the supply side is addressed by controlling or influencing store management and policies. In non-remote areas there needs to be a survey of the sources of food supply, their accessibility and how access to healthy foods can be improved.
- It is essential to give the community ownership and full involvement in the project such that they feel they have a vital stake in the project and its outcomes. This needs to be supplemented with education and training in nutrition, diet and the links to good health and wellbeing.
- There also needs to be suitably support and resources for the community.
- There needs to be full regard to the socio-economic and physical environment in which the intervention projects are being implemented. Reference has already been made to the food supply environment but regard also needs to be had to housing condition including food storage and preparation facilities, schools and sporting facilities.
- The interventions need to be designed having regard to the objective of scaling them up if they prove successful. This would require the involvement of representatives of relevant governments who would be involved in any scaling up.
- Sport is an effective way to promote healthy lifestyle among indigenous children and adolescents.
- The involvement of relevant, local schools and care-givers needs to be factored in for programs targeting children.
Michael Lambert is a former Secretary of NSW Treasury and a director and senior adviser on health economics at the Sax Institute, a not for profit organisation that seeks to connect health research with health policy and programs to enhance population health.