The 40-year-old actress admits her husband, Coldplay frontman Chris Martin, can`t bear to listen to music when he is at home, but as soon as he goes out, she puts on her favourite hip-hop records and heads into the kitchen.
She said: "He can`t have background music on; it has to be 100 per cent of his attention.
"But if he isn`t at home, I turn on the hip-hop - I`m like a bad mutha rapping along to every word as I cook."
Gwyneth - who has children Apple, eight, and Moses, six, with Chris - also admitted she is a "perfectionist" who regularly struggles to sleep because she is plagued by "dumb" concerns.
She told ES magazine: "The dumbest things [keep me awake]. I am a perfectionist. It`s a very neurotic impulse. I could stress about anything from a typo on my website to juggling all my upcoming tasks at once. I find I`m pretty mellow during day, but when I get to bed my heart starts beating and I stress out."
And despite her health-conscious persona, the `Iron Man 3` actress admitted she still smokes the occasional cigarette.
Asked what she bought with her first pay cheque, she said: "Probably cigarettes. I still buy the occasional pack."