Cameron Diaz thinks social media is a "crazy-ass experiment".
The 'Bad Teacher' actress - who married rocker Benji Madden in January after eight months of dating - quit online networking in 2014 because she thinks it is "dangerous" and doesn't understand why people place so much value on the opinions of people they don't know.
She said: "I think social media is a crazy-ass experiment on society.
"The way people use it to get validation from a bunch of strangers is dangerous. What's the point?"
Despite her slender figure, the 42-year-old beauty insists she is happy to indulge in sugary foods but knows it is important to have things in moderation.
She told the new issue of Britain's Cosmopolitan magazine: "Wellbeing is an equation. Remember, you don't have to have the whole cake, you can have a piece. Don't deprive yourself. Have fun. Just be self-aware.
"If your equation is 80% good, 20% bad most of the time, then a little movement toward the centre isn't going to affect you much."
And Cameron believes people should push themselves to exercise regularly and not make excuses.
She said: "You have to just do it. Once you commit and really put in the effort, your body goes, 'Oh, it's not OK to be without this.' People say, 'My body rejects exercise.' No, it doesn't. Your mind rejects exercise."