Oprah Winfrey has ditched her diet plan - for one day as she celebrated turning 64.

The actress-and-presenter - who is a celebrity ambassador for Weight Watchers - admitted she was tucking into a second slice of her favourite cornbread as a birthday treat.

Oprah revealed on Instagram: ''This is me on my birthday having cornbread and black-eyed and field peas and rosé.

''Thank you John Travolta for the glass and I have to say, yes I did. I had two pieces. This is my second piece. Why? Because it's my birthday and you can have two pieces on your birthday. Peas, cornbread - favourite meal.''

The 'Greenleaf' star was thrown an enormous party over the weekend by her OWN staff and presented with a bright green layered cake.

But she replied to a fan asking about how she was doing keeping to the Weight Watchers points programme amidst the celebrations.

Oprah wrote: ''Doing great. Just had a 4 point lunch white bean soup and chopped chicken salad. And 6 Mary's Crackers ... Love #MarysCrackers ... the black pepper ones.''

The star was also delighted to receive her own action figure for upcoming Disney movie 'A Wrinkle In Time'.

She said; ''This make me so happy, My own action figure doll from 'A Wrinkle In Time' ... Oh, I love it, I love it , I love it!''

Oprah plays Mrs. Which in the upcoming Disney movie, an adaptation of the popular 1962 science fiction novel of the same name by Madeleine L'Engle which kicked off her 'Time Quartet' series of books.

Ava DuVernay directs an all-star cast which also includes Reese Witherspoon, Chris Pine, Mindy Kaling and Zach Galifianakis.