The biggest risk factors for poor health worldwide are high blood pressure, smoking and alcohol use, a major new study has shown.

According to the Global Burden of Disease Study 2010, which has just been published, over nine million people died around the world in that year as a result of having high blood pressure. This made it the health risk factor that took the greatest toll.

It was followed by smoking and alcohol use, which in recent decades, have overtaken child hunger as bigger risk factors to health.

The study, which was carried out by an international team of scientists, looked at over 40 specific risk factors in 1990 and 2010.

"We looked at risk factors for which good data are available on how many people are exposed to the risks and how strong their effects are, so that our results can inform policy and programmatic choices," the scientists said.

They found that the risk factor with the biggest increase in health burden was a high body mass index (BMI) - in other words, being overweight or obese. It was ranked 10th in 1990, but rose to 6th in 2010.

In fact, that year, over three million people died as a result of their excess weight. This figure was three times higher than the number of people who died from undernutrition during the same period.

The risk factor with the biggest burden in western Europe was smoking and worldwide, over six million people died as a result of the habit in 2010.

The scientists said that overall, they are seeing ‘a growing burden of risk factors that lead to chronic diseases in adults, such as cancer, heart disease and diabetes'.

"The good news is there are lots of things we can do to reduce disease risk. To bring down the burden of high blood pressure, we need to regulate the salt content of food, provide easier access to fresh fruits and vegetables, and strengthen primary healthcare services," the team said.

Details of these findings are published in the medical journal, The Lancet.