This disease is big. It's growing. It's scary and it's very expensive. In the next five years, diabetes will become the No.1 one cause of death and illness in Australia, which now has 1.5 million people living with the disease, according to Diabetes Australia. By 2025, it's estimated 3 million people will be affected. More than 85 per cent of all diabetes cases are type-2, which costs an estimated $14.6 billion each year, leading to the same serious types of complications as type-1 diabetes. And studies now show young people with the more preventable type-2 diabetes are twice as likely to die from the disease as those with type-1.

It's a public health time bomb.

Put simply, diabetes is a chronic condition in which a person has high blood sugar.

''The reason we have an epidemic of type-2 diabetes in Australia is because we have all the contributing factors,'' says Professor Greg Johnson, chief executive of Diabetes Australia. ''Sedentary lifestyles, easy access to processed food, weight gain and a multicultural society which includes people from high-risk genetic backgrounds, such as indigenous, Chinese, Indian and the Pacific islands.

''There's no doubt weight gain is a big driver, but it doesn't explain it all,'' Johnson says. ''There are thousands of people with type-2 diabetes who are a healthy weight and have a pretty healthy lifestyle.''

As well as those with existing diabetes, another 2 million Australians have ''pre-diabetes'', showing abnormal blood glucose levels. About 35 per cent to 40 per cent of this high-risk group will go on to develop type-2 diabetes in the next five to 10 years, says Professor Jonathan Shaw, associate director of Baker IDI Heart and Diabetes Institute.

Coming up through the age ranks is a stream of young people being diagnosed with the ''silent killer''. Once called age-related onset diabetes because it was typically diagnosed in people after age 40, type-2 diabetes is now being diagnosed in younger adults, teens and occasionally children, Johnson says.

The Melbourne Royal Children's Hospital diabetes clinic typically treats about 50 to 60 adolescents with type-2 diabetes at any one time. ''That's been fairly constant over the last 10 years,'' says paediatric endocrinologist Dr Matt Sabin. ''The youngest person I've treated was about 12.'' Young people find it harder to control diabetes, Sabin says, which helps explain why they get more complications younger, such as relying on a dialysis machine to support their failing kidneys.

HSC student Taylor Eddy, 18, from the Central Coast, was diagnosed with type-2 diabetes last year, after experiencing excessive thirst, headaches, sudden bouts of hunger and dizziness. ''When I was diagnosed I felt pretty down and daunted because I knew it was going to impact the rest of my life,'' Eddy says. ''I was kind of expecting it though, because my mum and grandmother have it, too. We are indigenous so more likely to get it, but I didn't expect it this young.

''I've found it hard to increase my exercise because of the time pressures of HSC, but a lot of sugar has come out of my diet, especially chocolates and lollies, and I eat less now overall and have lost some weight. It's really hard though when all my friends are eating chocolate, but they are very strict on me. So is my nan who I live with. They are my biggest support.''

Those at the forefront of tackling diabetes are frustrated by Australia's lack of a national approach, since type-2 diabetes is preventable. ''In research settings, healthy lifestyle programs for people at high risk of diabetes, reduce the risk of progressing to diabetes by about 60 per cent,'' Shaw says. ''Real world community interventions, with fewer program resources and where participants may not be as motivated, reduce the risk by 30 per cent.

''The problem is we can't get enough people into these programs to make a real difference,'' Shaw says. ''And when we focus on prevention in the general population, not just the high-risk groups, it's really hard to make a dent because that group is so large, and because eating and activity habits are so hard to change.''

In affluent countries, underexertion and overconsumption become the norm. ''That's why we also need population measures,'' Shaw says. Finding ways to engineer more activity in our lives is one measure Shaw supports. So is taxing unhealthy foods or subsidising healthy foods. ''It's hard to get it right though,'' Shaw says, pointing to other countries' failed attempts. ''When Denmark attempted taxing high-energy foods, the Danes went to Germany to buy their treats instead … In the end though, this will be one of the important strategies that'll actually make a difference.''

A hard-hitting approach is vital, says Mike Daube, a professor of health policy at Curtin University, who has spent decades tackling the public health problems of smoking and excessive drinking. ''We've learnt from our experience with the tobacco industry that a bit of goodwill won't do the trick. Expecting the food industry to do the right thing [by not advertising unhealthy foods to children for example], without regulation is pie in the sky,'' Daube says. ''Soft, happy education doesn't work either,'' he adds, pointing to Western Australia's LiveLighter media campaign as an example of what is needed.

Recent campaign ads aim to scare people off sugary drinks by showing graphic footage of gurgling ''toxic'' fat surrounding internal organs. ''Drinking sugary drinks is contributing to our expanding waistlines leading to higher rates of heart disease, type-2 diabetes and several cancers,'' LiveLighter campaign director Maria Szybiak says. Australia's consumption of sugary drinks per head of population ranks in the top 10 in the world, with Australians guzzling 1.28 billion litres in 2012.

The main role food plays in causing diabetes is simply through providing too much energy, says Shaw. ''But there's reasonable evidence that sugar sweetened beverages have an effect above and beyond providing surplus calories.''

Kate Di Prima is a paediatric and family accredited dietitian who sees children from about the age of 12 showing early signs of type-2 diabetes. ''They are invariably over a healthy weight, eat too much overall and too much carbohydrate [such as from bread, rice, pasta] at one time. 'Discretionary foods' such as cakes, biscuits, pies, juices, cordials and soft drinks can make up 20 per cent to 50 per cent of their total energy intake.''

So what's it going to take to stem the tide? ''You can't expect prevention to work without a nationally co-ordinated plan,'' Johnson says. Diabetes Australia has released its National Diabetes Strategy and Action Plan, focusing on early detection, management and prevention.

But Daube says the community has to fuel any real change. ''We need the type of community concern and outrage that we had to fuel change with tobacco and alcohol. We're just not seeing that yet.''

Hear the tick

• Every day 280 Australians will develop diabetes. 

• Almost 100,000 Australians developed diabetes in the past year. 

smh.com.au