Reese Witherspoon is craving seaweed.

The 'This Means War' actress is currently pregnant with her third child and has been waking in the night with desperate urges for strange foods.

A source close to Reese - who married second husband Jim Toth last year - told Closer magazine: ''Reese has been waking up at 3am and craving seaweed smoothies, pickles and peanut butter all together, plus chicken wings smothered in barbecue sauce.''

And it isn't only at night when the 36-year-old actress - who also has children Ava, 12, and Deacon, eight, from her marriage to Ryan Phillippe - has been craving particular foodstuffs, she also fills up on fruit and yoghurt in the day time.

The source added: ''In the day, she only wants bananas and strawberry yoghurt - by the litre. She usually sticks to a healthy diet so she's hoping the cravings stop soon.''