The 'Iron Man 3' actress - who recently released her new healthy cookbook 'It's All Good' - initially became interested in improving her diet after 'The Great Gatsby' star ''planted a seed'' in her mind by warning her about ''dirty meat'' more than twenty years ago.
The 40-year-old blonde beauty told The Observer newspaper: ''He was vegetarian and he'd talk about how dirty meat is and how bad factory farming is. I haven't eaten red meat in 20 years, and although Leo's not totally responsible, he definitely planted a seed.''
Gwyneth became more interested in healthy eating when her father Bruce was diagnosed with throat cancer in 1999 and passed away in 2002, but insists her diet still isn't perfect.
She said: ''All I do is try to eat and cook real food, the way our ancestors would. It's funny how people react, as if it's revolutionary that I don't want my children to eat Oreos, or the English equivalent, every day. I believe in real food, things being delicious, and butter, in minimally processed delicious foods and raw milk cheese and properly raised chicken and line-caught fish.
''But I'm a realist and I have kids and I love Oreos too, so honestly I'm not rigid at all.''
She said: ''My husband prefers my food to any other. It's very sweet.''
However, she is not impressed with how their children Apple, eight, and Moses, seven, pronounce some foods.
She said: ''I've lived in England for 10 years and the accent is the most beautiful in the world, except for how you pronounce 'pasta' as 'pasta' instead of 'pah-sta.'
''I'm sort of joking when I say this but I really don't want my children speaking that way.''