Gillian Anderson used to be too ''exhausted'' to make an effort with her appearance.

The 45-year-old actress admits she is embarrassed when she looks back on some of her sartorial choices at the height of her fame in 'The X Files' and even though she hated her look on the sci-fi show, she couldn't be bothered to change when she wasn't filming.

She said: ''The odd thing is that even when I was put in those horrible pastel Lycra suits, there wasn't a single part of me that considered saying, 'Woah, wait one second.'

''Likewise with the hair, I was made to have red hair, styled in a particular way, but you'd have thought I might have done something with it off screen. Still, I didn't bother because I was so exhausted.

''So for nine years I went to work and was somebody else, without devoting any time or attention to the way I looked.

''Now, when I look back at images of myself in those horrible fashion decisions with my weight fluctuating all the time, I can't believe it.''

Gillian admits she can see a lot of herself in Kristen Stewart, who is often criticised for her surly expressions.

She told Britain's Glamour magazine:'' Do you know what's funny? Sometimes I'll see photographs of myself in the early days of 'The X Files' and I think my attitude to the whole thing was very similar to Kristen Stewart's.

''There's a very similar look in my eye, slightly defiant, slightly bored. All I ever got was, 'Smile! Smile!' when I didn't want to smile. And I really wish somebody at that time had told me, 'You know that it's OK to be who you really are.' ''