WOMEN who gorge on junk food could cause heart disease in at least three future generations of their family, scientists believe.

Too many hamburgers, pizzas and fizzy drinks increases the risk of the illness in their children, grandchildren and great grandchildren - even if their offspring eat healthily.

And it does not matter if they have boys or girls - because the harm is passed on by fathers, as well as mothers.

This is a landmark discovery as it had been thought faulty mitochondria could only be inherited from the mother.

Experiments on obese female mice fed foods high in fat and sugar before and during pregnancy found damage to the heart's mitochondria - throughout the bloodline.

These are the tiny power stations of cells that provide us with energy. Defects lead to

muscle weakness, heart failure and even death.

What's more, male offspring handed down the same heart problems - even after mating with healthy females fed a normal diet.

Although the study was carried out on lab rodents, the US team believe the findings will also apply to humans.

Co-senior author Kelle Moley, a professor of obstetrics and gynaecology, said: "We know obesity in pregnant mothers raises the risk of future heart problems for her children.

"But we have shown, at least in mice, that these heart problems don't stop with a single generation.

"They are passed down by both the male and female offspring of obese mothers, even when the offspring eat a normal diet.

"This was a bit of a surprise - problems with heart mitochondria seemed likely to be passed down only through females, through the mitochondrial DNA present in the egg that we inherit only from our mothers.

"Now that we have shown mouse fathers pass this down as well, we have to start studying changes in the DNA of the nucleus in both the egg and the sperm to make sure we understand all the contributing factors."

Fatty and sugary foods are known to endanger heart function. But the study published in AJP-Heart and Circulatory Physiology revealed "multigenerational heart problems".

These remained even when the offspring were not obese themselves and ate a normal mouse food throughout their lives.