Actress Julia Roberts has dismissed fad diets and strict fitness programs and credits her genes for keeping her thin.

The 'Pretty Woman' star manages to stay healthy by working out once in a while. The 40-year-old is grateful for her genes for her slimness.

Contactmusic.com quoted her as saying: 'I have been working out, but listen, it is 97 percent genetics. Don't let anybody tell you any crap about anything else, because that's what it is - 97 percent genetics and three percent just get your ass moving. Because I've never met a cookie I didn't like.'