Being just four pound overweight can increase the risk of suffering a heart attack by almost a fifth, according to new research.
The large-scale study found that being overweight does actually cause Britain’s biggest killer as well as diabetes.
More than 200,000 were involved and it found that a one-unit increase in body mass index, which measures body fat levels, raises the risk of heart failure by 17%.
One BMI unit means different weights for people of different heights, for someone 5’10” it’s 7lbs, for someone 5’4” it’s 6 pound.
Obesity leads to higher levels of insuling, higher blood pressure, higher cholesterol and inflammation and more cases of diabetes.
Professor Erik Ingelsson, of Uppsala University, Sweden, said: “This knowledge is important, as it strengthens the evidence forceful societal measures need to be taken to counteract the epidemic of obesity and its consequences.”
"We knew already that obesity and cardiovascular disease often occur together," said Dr Tove Fall, a researcher at Uppsala University in Sweden who led the study along with researchers at Imperial College London and the University of Oxford.
"However, it has been hard to determine whether increased BMI as such is dangerous.
"In this study we found that individuals with gene variants that lead to increased body-mass index also had an increased risk of heart failure and diabetes.
"The risk of developing diabetes was greater than was previously thought."