Lisa Marie Presley's Slim-Down: I'm at My Teenage Weight

Like millions of women, Lisa Marie Presley has tried fad diets over the years – with mixed results. Recently spotted in Australia looking slim, the singer-songwriter has finally discovered what works.

“Eating clean and organic is best,” Presley, 46, tells PEOPLE from Down Under, where she and her husband, guitarist Michael Lockwood, are touring in support of her album Storm & Grace.