Mischa Barton: Slim 'n Trim in the Sunshine State

Kicking off the week with a fay of fun in the sun, Mischa Barton was spotted enjoying the warm weather on Miami Beach on Monday (January 2).

The former "OC" star wore a fashionable beach outfit consisting of a bikini top and blue shorts as she mingled with friends and cruised about the Atlantic waters on a wave runner.

Looking slim and trim these days, Miss Barton has credited her toned figure to her changed diet and exercise.

According to the NY Post, the 25-year-old has been telling friends that her key to shedding the pounds is "eating really healthy, keeping a mostly vegan diet and running."

Enjoy the pictures of Mischa Barton out on Miami Beach (January 2).