Mischa Barton looks healthy and happy in bikini top on Miami beach

Yo-yo dieter Mischa Barton looks healthy and happy in a bikini on Miami beach

Not in The OC, anymore: Mischa Barton goes back to her beach roots, but this time in Miami as she sunbathes today

In the shade: The actress chills on her sun lounger while adjusting her funky sunglasses

Me? Walk? Mischa was escorted around in a beach buggy

Just perfect: Mischa has struggled to maintain a consistent weight, but she seems to have found her balance

Happy memories: Mischa looked like her OC character, Marissa Copper, with the well-executed beach look

Alone time: Mischa enjoyed the beach with just a book and a drink

Cover girl: Mischa looked stunning as she smiled in the sunshine

Demure: Mischa cut a retro figure in red lipstick and stripes

Time to go: After her sunbathe, Mischa was joined by a male friend who gallantly carried her drink

Travelling in style: The pair then headed off on a beach buggy

Picturesque spot: Before heading to another section of the beach to continue soaking up the sun

Time for some refreshments: The actress headed to grab lunch at a restaurant later on

Menu please: Mischa sits at the table ready to order