One Direction's forthcoming feature film will look at what happens inside a fan's body when they hear the group's tunes.

The British boyband are set to release their debut movie later this year in the shape of This Is Us, which is being directed by Morgan Spurlock.

Speaking to the New York Post, the Super Size Me man revealed that the 3D flick is set to go beyond just the lives of the 'Kiss You' quintet.

Spurlock said that they have spoken to a doctor to get the lowdown on what happens internally when a Directioner listens to their heroes. He said:

"We ask the question 'Why them?'. We talked to this one doctor who tells us what happens inside a girl's body when she hears One Direction - like what happens in her brain and what goes on inside of her."

The director had previously revealed that This Is Us could potentially feature scenes of the boyband topless.