Gwyneth Paltrow has quite an appetite!

During an appearance on the British reality show Jamie and Jimmy's Food Fight, starring famous foodies Jamie Oliver and Jimmy Doherty, the 40-year-old Academy Award winner was asked to participate in a silly but sweet challenge.

"I embarrassingly tend to eat more than the men that I eat with," confessed Paltrow, who once followed a strict macrobiotic diet.

Doherty, 37, first explained the rules of the game. "You eat a marshmallow, hold it in your mouth, I eat one, and we continue until our mouths are full and whoever gives in first is the loser."

Co-host Oliver, 37, then added a twist. "Every time you put a marshmallow in your mouth, you have to say, 'chubby bunny!'"

Paltrow -- who released her first cookbook in 2011 -- agreed and volunteered to go first. Before inserting the second fluff into her mouth, Paltrow giggled and said, "This is so gross!"

To see Paltrow stuff her face, watch the video above now!