"I went skinny-dipping in Bermuda and got caught by the police," she told The Mirror.
"I was working on the cruise ship but wasn't on telly yet, which is a good thing or there might have been pictures. Although I was young and firm then."
McDonald's co-presenters Carol McGiffin and Andrea McLean also admitted they had exposed their bodies in public in the past.
"I was on a bamboo raft in the jungle in Thailand and there were these really annoying, loud German tourists behind us," said McLean.
"As they passed our raft, without saying a word to each other, my friend and I stood up and mooned at them."