After decades of research showing the impossibly close link between obesity and heart problems, a Swedish study has finally proven what we've long suspected: Excess weight does cause heart disease.
Obesity alone - without other risk factors like high cholesterol, inactivity and diabetes - raises a person's risks of heart disease by nearly a third, previous research has shown.
At last, the Karolinska Institute researchers used a method called Mendelian randomization prove that high BMI is a direct cause of heart disease.
And that meas that a third of the world's population - the proportion of humans that are now overweight or obese - could be on a path toward the number one cause of death without lifestyle changes and medical interventions.
At long last, a Swedish study has finally shown that the link between obesity or excess weight and cardiovascular disease is a causal one
The first study of its kind was based on hundreds of thousands of Britons and a revolutionary statistical technique called Mendelian randomization.
This enabled the Swedish team to use genetic variants as a tool to show the causal relationship between cardiovascular disease and BMI (body mass index).
In particular, they discovered as BMI and fat mass increased so did the risk of many more than half a dozen conditions - especially aortic stenosis.
This where the valve controlling the flow of blood from the heart to the body's largest blood vessel, the aorta, narrows and fails to open fully.
If left untreated it can lead to serious problems - and even death.
Professor Susanna Larsson, of the Karolinska Institute, Stockholm, said: 'The causal association between BMI and fat mass and several heart and blood vessel diseases, in particular aortic valve stenosis, was unknown.
'Using Mendelian randomization we found that higher BMI and fat mass are associated with an increased risk of aortic valve stenosis and most other cardiovascular diseases, suggesting that excess body fat is a cause of cardiovascular disease.'
The 'fat but fit' theory suggests a bulging waistline is not harmful as long as other metabolic factors like blood pressure and glucose are within recommended levels.
But evidence is growing that this is wrong - an may be sending out the wrong message to millions of people.
Using data from 367,703 men and women aged 40 to 69 they identified 96 gene mutations linked to BMI and body fat mass to estimate their effect on 14 cardiovascular diseases.
The participants were from the UK Biobank, which holds biomedical information on half a million people. They were all of white British descent and aged 40 to 69.
Those with variants predicting higher BMI were at increased risk of aortic valve stenosis - as well as a host of other life threatening conditions.
These included heart failure, deep vein thrombosis, high blood pressure, peripheral artery disease, coronary artery disease,
