As per a new paper released by doctors from Britain and Sweden, heart problems and diseases linked to obesity many are much worse and deadly than previously estimated, and health problems which emerge out of being underweight, on the other hand, have been overestimated.

With the paper, the doctors are looking to "fine-tune" BMI or Body Mass Index, an years old tool which is used to measure obesity and the health risks associated with it.

Various studies carried out previously have already managed to find a substantial and strong link between BMI and an increased risk of developing cardiovascular troubles, diabetes and some deadly cancer forms.

Being underweight or having a low BMI, on the other hand, has been linked to increased risk of deaths from respiratory disease and lung cancer, but the current paper says that scientists could not find any such link during the present studies quoted.

"The findings are important, because they imply that obesity programs could yield major health benefits. Suggestions to the contrary are probably misguided", the study says.

The papers have been published by the British Medical Journal.