Gwyneth Paltrow works hard to keep slim.

Celebrity fitness instructor Tracey Anderson says the 41-year-old actress had some ''problem areas'' which made it difficult to keep trim, however her commitment to a strict diet and a gruelling six-day workout regime keep the star in top shape.

Tracey told E! News: ''Gwyneth had some problem areas when I first met her, and now she is in great shape.

''She is just so dedicated, and what's great with her is that she's so consistent, focused and she actually puts the work in.

''For eight years I have designed a new program for her every ten days, and she does it six days a week. It's not two hours, it's more like an hour and fifteen minutes.''

The fitness guru - who has worked with the likes of Victoria Beckham and Cameron Diaz - insists not all celebrities are gifted with perfect bodies and they fall victim to the same food vices as the average person.

She added: ''There is not a trick, and everyone is just not genetically blessed. Some people look at celebrities and they think 'oh, they have it better than me, and it's just not true!

''Some celebrities are doing some unhealthy things. But someone like Gwyneth, I like to celebrate because she is really just a good example.''