Start with a tape measure and run it around your belly.

If you are a man more than 94cm around the waist or a woman more than 80cm, don't panic but do go and see your GP. If you are then checked for fasting cholesterol levels (including triglycerides and HDL cholesterol), blood pressure and fasting sugar levels and two out of four of these are abnormal then you have what is called the metabolic syndrome, sometimes called syndrome X.

This cluster of risk factors means that you are three times more likely to have a heart attack or stroke, twice as likely to die from these events and five times more likely to develop diabetes if you don't already have it.

If you have this syndrome you are not alone. It is now estimated that one third of Australia's population is in this category. This puts the metabolic syndrome and diabetes way ahead of HIV/AIDS as a cause of sickness and death and yet this is little known and has not had the attention it deserves until now.

So how can we lower our risk and prevent these serious illnesses in later life? The good news is that a small reduction in weight of 5-10% without regain can dramatically reduce risk. This can largely be achieved by lifestyle measures alone although some people may require medication.

Don't go on a fad diet - just make healthy choices in food including fruit and vegetables, legumes, nuts, lean meat, fish, low fat dairy products and use poly and mono-unsaturated oils like olive oil, but use these sparingly. Be careful with portion size and eat slowly and enjoy food at the meal table without the TV on.

As regards physical activity whatever you are doing, do more - just walking is good and do it at your own comfortable pace and maybe add in some upper body exercise with light weights. Look for opportunities to move around during your day as much as possible. Reduce sedentary activity such as TV viewing and computer use as much as possible and if unavoidable then compensate with extra physical activity.

It's all about energy in and energy out and creating a deficit to lose weight and maintaining a balance to prevent initial gain or regain after weight loss.