Gwyneth Paltrow says she was left ''hallucinating'' after a 10-day cleanse.

The 'Iron Man 3' actress is known for being active and eating healthy, but admits she has tried fads like juice cleanses in the past which did her more harm than good.

She explained: ''I've done juice cleanses in the past, and in my twenties I did the Master Cleanse, which left me hallucinating after 10 days. Be aware: a juice detox can crash your metabolism and lead to future weight gain.''

Although she's committed to healthy living, the 40-year-old beauty reveals she does indulge in naughty treats every now and then - including wine and cigarettes - because it provides some ''balance'' in her life.

In a self-penned article for The Telegraph newspaper, she wrote: ''Stay away from processed foods, though cutting them out completely is no fun and can ultimately lead to a binge.

''Allow yourself programmed treats; I often have a glass of red wine in the evening and smoke a cigarette on a Saturday. I love those moments because they are just the right amount of naughty. That balance keeps you vibrant. You have to live your life, after all.''

Along with a good diet, Gwyneth insists exercise is important and says she finds time to work out five days a week.

She added: ''Keep up consistent exercise. I am dedicated to the Tracy Anderson Method and it has completely changed my body. Still, when I first started working with Tracy, finding motivation was hard.

''She advised me to think of exercise as an automatic routine, no different from brushing your teeth, to avoid getting distracted. Now it is part of my life - I exercise Monday to Friday at 10am and always stick with it.''