This is a shorter version of an article that appears in the latest issue of Perspectives, an opinion-led journal published by Baker IDI Heart and Diabetes Institute.
It’s predicted that two-thirds of the Australian population aged over 25 will be overweight or obese by 2025 if current trends continue. To paint the picture more crudely, this means that a person of normal weight will soon be the exception rather than the norm.
These predictions, using data from the Baker IDI-led AusDiab surveys on more than 11,000 Australians who were tracked over five years, made national headlines late last year.
In fact, we’ve been hearing about an obesity epidemic for a few years now, but just how did we get to this dire point?
An evolutionary bind
Humans have evolved to be highly inept at weight maintenance. The propensity to lose weight quickly would’ve been a particularly harmful characteristic in times of famine. So part of the reason why we find weight loss so difficult is because it goes against our basic design.
A popular theory explaining this view is the thrifty gene hypothesis. It proposes that the thrifty genes that predispose people to diabetes and obesity were historically advantageous during times of food scarcity.
But in modern societies with abundant food, this genotype is preparing individuals for a famine that never comes. When you introduce over-nutrition, increases in portion sizes, increases in fast food intake and lack of physical activity, the result is a disaster.
So what we’re facing is a twentieth century phenomenon where genetic and environmental factors have spectacularly collided. But only in the past decade or two has obesity started to be mentioned as a major disease burden.
Even the World Health Organisation (WHO) didn’t formally recognise obesity as a global epidemic until 1997. And diabetes, which is intrinsically linked to obesity, was only recognised as a chronic, debilitating and costly disease by the United Nations General Assembly in 2006.
In fact, the data on diabetes is equally formidable, with its prevalence increasing beyond what can be expected because of our ageing population.
In Australia alone, the number of diabetics doubled between 1981 and 2000, and projections show as much as 17% of our population – that’s nearly one in five people – could have diabetes by 2025.
When people talk about the problems of diabetes and obesity, the biggest problem they identify is how fast their prevalence has increased. This suggests there’s been some sort of environmental trigger other than eating too much and exercising too little.
All the usual pathways of science can’t explain why the increases have been so rapid. But while we grapple with numbers, the chance to reverse this trend is all but being lost.
In 2008, the Council of Australian Governments (COAG) set a target to increase the proportion of Australian adults at a healthy body weight by 5% from 2009 to 2017.
While target-setting is a critical component of a obesity prevention policy, we recently analysed the changes in current weight gain required to meet this target and the news is grim.
It’s been well demonstrated that the prevalence of healthy weight is expected to plummet in the coming decade with a likely decrease among Australian adults from 35% in 2010 to under 30% in 2020 if current trends persist.
For diabetes, COAG’s target is to be back to 2000 levels by 2025. We modelled how long it’d take to get to that figure based on our current intervention practice. And the numbers again tell a shocking story – we won’t even get close.
Expanding health budget
The number of the obese and diabetics continue to take most people by surprise even though we are only beginning to come to grips with the rapid escalation of these illnesses. In coming to terms with this epidemic, we must also face the associated economic cost of obesity.
Research published in the Medical Journal of Australia (MJA) in 2010 showed that the total direct cost of overweight and obesity in Australia is $21 billion a year.
In 2007-08, that represented close to one-fifth of Australia’s entire $103.6 billion health expenditure budget. More concerning is the fact that just over $3 billion was allocated for preventive services or health promotion in the same year.
With such feeble efforts, it’s easy to see how the community and policy makers might become disillusioned and question our ability to halt, let alone reverse the obesity epidemic.
We need to set realistic and practical targets because we know that any road to major change will take decades – even with major investment, commitment and goodwill. In this context, perhaps maintaining current levels of healthy weight should be considered a marker of success.