She admits that she's no style expert, but TV girl-next-door Jennifer Aniston has become one of America's most influential trendsetters - without even trying.

  Jennifer Aniston never wanted to be a poster girl. Really, she didn't. But somehow, she became the Ninties' answer to Farrah Fawcett: TV's prime-time paragon of feminine beauty, imitated everywhere from the halls of high fashion to the most mundane suburban malls.

  Aniston and Fawcett do have a few traits in common: the bountiful hair, the perfect teeth, the well-scrubbed face and the very lithe limbs. But while Fawcett came to exemplify a bigger-than-life, Cosmo-girl sexiness, Aniston - like her character, Rachel, on "Friends," which is now in its sixth season - is comfortably anti-glam. She's funny and self-deprecating and, no matter how well-coiffed and toned, devotedly girl-next-door - more Donna Reed than Madonna. Maybe that's why Aniston's face sells more magazines than any other star's. She may have the so-called Sexiest Man Alive as her boyfriend, but she's still a woman others can relate to.

  "I wonder what that is," she says when asked about her influence on fashion and beauty trends. "Isn't it funny? Your image of yourself is so different than other peoples'. I'm not good at hearing positive things - I can accept criticism better. I'm very critical of myself - which gives me somethhing to work on. I want to evolve."

  Of course, it's not easy to evolve when your required to do so in public. Aniston's efforts at self-improvement aren't always a big hit with her critics or her fans. Most recently, she's been lambasted for getting too thin, working out too much and wearing her hair too big at this year's Emmy Awards. "Lately, I've been reading that I'm too skinny," she says with a sigh. "A few years back, they said I was too curvy. I guess when I was rounder, I was easier to relate to. The media builds you up and tears you down. What the magazine readers are missing is that the glamour they see on the cover isn't real, and it isn't easy. Those pictures take a lot of work. Being thin is hard work!"

  Aniston insista that her thinness is not due to obsessive calorie-counting. "You can get into an exercising zone where it feels so great it's addictive," she says. "I swear, I eat more now than I ever did in my life - I just work out more, because it feels great. And if that old cheeseburger and fries start to look irresistible to me, I'll eat it. I never wanted to be a spokesperson for weight loss. In fact, I feel the same now as I did five pounds ago." She says she hasn't lost weight to please anybody except herself, declaring, "If someone loves you more if you're thinner, get rid of them!"

  As for her famous mane, Aniston has gladly abandoned the now-classic Rachel layered 'do ("All I have to say about that, looking back, is, 'What the hell was I thinking?' " she says) in favour of this year's longer, sleeker, blonder look. Sometimes I loose perspective on how light I've actually gone," she says. "You go out in the sun and suddenly you're Summer Blond. But it's fun to change. Michael Canale [in Beverly Hills] highlights my hair so well - he's got that touch, the natural touch. And if I want to look funky, he won't do that. For a while I had dead, trashed, burnt hair - they ironed it so much for the show. I'm trying to let them go with my natural wave this season. But I'm always thinking, when I change it a little, am I ready for the beating I'll take in the press? You never get used to it. It always bruises your ego."

  Despite all the attention that's been paid to her look, Aniston comes right out and declares that she doesn't have much style. "I remember thinking 'couture' was a designer," she says. "I thought, wow, this guy is everywhere - on every label! That's how much I know."

  She has been learning quickly however. "I've worn Prada and Dries Van Noten, and I love Susan Lazar's clothes - they're for real people, and accomodate all bodies," she says. "I like everyday clothes. Even at awards shows, I don't like feeling like I'm being at all showy. So sometimes for big events I hire a stylist - I'm not great at pulling clothes together in the 'proper' way. And you certainly don't want to piss Joan Rivers off."

  For a second, it seems like she means this. The she adds sarcastically, "Now there's a woman with taste! I stay far away from her. To me, personal style is whatever is the most comfortable. Heels are my nightmare - they make me break into a sweat. I pray for lawn events, so I can wear flats."

  Not that Aniston doesn't enjoy the occassional shopping spree. "I admit I love clothes," she says. "And I buy clothes. But they sit in my closet." Both she and Brad Pitt are unapologetic "homebodies," she adds. "I like a pair of comfy pants, flip flops and a T-shirt. And when we pick a restaurant, my criteria is: Where can I wear this?"

  What about the legions of paprazzi hiding in the bushes, waiting to catch her in the least favourable circumstances?

  "Oh, it's happened where they've taken a picture of me looking like a slob," she says. "I'm used to it. I just give up. You can't control it. As long as I'm not bending over with my crack showing, I don't care."