Dakota Fanning ''fainted'' during her first costume fitting for 'The Alienist'.

The 24-year-old actress wasn't a fan of the tight-fitting corset she wore for her role in the period drama miniseries, but the garment helped her get into character as police secretary Sara Howard.

She said: ''One of the most important things about 'The Alienist' was the costumes.

''I fainted during my first fitting. I had just gotten off the plane and was swollen and jet-lagged.

''They put the corset on, and I said, 'I'm going down!' I had to sit. But I got used to it.

''My body completely changed. For better or worse, the corset puts you into the character. It affects everything you do: breathing, walking, sitting, standing, and definitely eating.''

The series was shot in Budapest and Dakota ''sobbed hysterically'' when filming wrapped and she had to return home to the US.

She told W magazine: ''We shot the show for almost seven months in Budapest, Hungary, which became my home. I sobbed hysterically when I had to leave my life there.''

When she isn't working the 'Runaways' actress is a big fan of reality TV and gets gripped by the romances that play out on screen.

Though Dakota isn't entirely sure if the shows are real, she thinks if they are faked, the stars deserve some credit for their acting talents.

She said: ''I'm obsessed with 'The Bachelor' and 'The Bachelorette'. Some of the best TV I've ever seen was the break up of Arie and Becca on last season's 'Bachelor'.

''That's what I'm trying to figure out: With reality television, if it's all set up and fake, then they've got the greatest actors in the world.''