Scientists in the North-East claim they have found a way to make junk food that's good for you.

The team says adding an extract from an exotic type of seaweed to cakes or fatty burgers could boost the fibre content - helping to fight against obesity, diabetes, heart disease and bowel cancer.

The seaweed extract, called alginate, increases the fibre content of junk food, which normally contain huge amounts of fat.

Professor Jeff Pearson, of the Newcastle University research team, said: "We're just not eating enough fibre, yet we need this to keep us healthy. The most practical solution is to improve the food we do eat.

"With a burger, for example, you would simply remove some of the fat and replace it with the seaweed extract.You'd have a healthier burger and it's unlikely to taste any different."

He said: "Adding the seaweed extract could quadruple the amount of fibre in white bread."

Researchers drew the extract from brown seaweed called lessonia and laminaria, found in the Far East, South America and parts of Norway and Scotland. It strengthens mucus, can slow digestion and the uptake of nutrients.

It is already used as a gelling agent and to thicken the head of premium lagers.