A higher body mass index (BMI) does not increase your odds of suffering a heart attack or premature death, according to new research that confirms past studies suggesting the standard measure of obesity used by doctors is not an accurate gauge of overall health.

The findings are based on a Swedish study of 4,046 genetically identical twin pairs with different amounts of body fat who were tracked for more than 12 years. The results, published in JAMA Internal Medicine, showed that those with a higher BMI do not have an increased risk of heart attack or mortality.

But the study did conclude a higher BMI is associated with an increased risk of Type 2 diabetes.

"The results suggest that lifestyle changes that reduce levels of obesity do not have an effect on the risk of death and heart attack, which contradicts conventional understandings of obesity-related health risks," said Peter Nordström, a researcher at the Department of Community Medicine and Rehabilitation at Umeå University.

"What the study does show is that there's a strong association between obesity and diabetes, which leads us to conclude that weight reduction interventions can be more effective against diabetes than when it comes to reducing the risk of heart attack and mortality."