And that's not just the case here in Victoria. Across Australia and in many other countries, people with mental health issues are more likely to suffer from a range of physical health issues including diabetes, cardiovascular disease, cancer and oral health issues.

The statistics are grim. Australians living with mental illness are:

But this is not set in stone. It's not the natural consequence of mental illness

It's for a host of reasons, and many of them are not about what an individual does and much about the way our services and systems respond to mental health issues.

The good news is there is much that can be done to address this inequity, and that many good things are already happening.

A few months ago, Melbourne hosted a two-day national conference that brought together doctors, psychiatrists, pharmacists, health service providers, researchers and people with lived experience of mental health conditions from across Australia.

Most were in services and organisations signed up to what is known as the Equally Well movement - whose simple premise is that a person living with mental illness should have the same right to physical health as anyone else. That they should be able to be equally well.

Some of those who are living with serious mental health conditions spoke at the meeting.

They talked about how medications had led to weight gain - not just the odd kilo, but significant gain in a very short time, often because of side effects they weren't warned about or weren't able to address.

The conference heard people living with a mental illness are less likely to be screened for physical health conditions (for example, cholesterol) and for lifestyle risk factors than other members of the community.

It heard that's a big issue with smoking, where many mental health services still think that quitting smoking is the last thing that people with mental health issues should have to deal with - something that's been described as "killing with kindness".

That's not to say health services should send people with mental illness off to bootcamp. But, in the case of smoking, there's growing evidence many people with mental illness do want to quit and that quitting can improve mental health - as long as they're offered the supports to do so when they're ready for them, which often is not the case.

The conference also heard that despite being sicker than many others in the community, people with serious mental illness use health services much less for a range of reasons including stigma and discrimination, and that when they do the system often fails them.

It's often too siloed where one part doesn't connect up with the other, and mental health professionals may not feel confident or think it's their business to consider physical health issues, and vice versa.

The Equally Well movement was officially launched a couple of years ago in Australia by Mental Health Victoria's patron Alan Fels, in his then role as chair of the National Mental Health Commission.

It is highlighting initiatives in innovative mental health services that are showing great promise, particularly around controlling weight gain and encouraging exercise for people when they are receiving mental health treatment.

But it also understands that there is more to good health than what we can do ourselves, particularly when we are already struggling with some issues.

It recognises that to prevent poor physical and mental health, people need access to:

This movement is sounding an alert across Australia, not just to people living with mental health conditions who want better advice and support to look after their physical health. It's also calling on GPs, all health services, medical colleges, social services and governments who know very well the cost of this burden and to see the whole person presenting to them.

To find out more, visit: equallywell.org.au/resources

Angus Clelland is chief executive of Mental Health Victoria