Hilary Duff down to bones and teeth?

"Young girls adore Hilary," a Duff family friend tells Star Magazine. "So many of them are wondering where the old Hilary went. She seems down to bones and teeth."

"She doesn't even look like herself anymore," says one fan. "I saw her on The View and she looked so different," adds another. "At first I thought she had her teeth done because her mouth looked so different [she did, according to Dr. Thomas Behm, who often viewing pictures of Duff told Star that he believes she had veneers]. But then I realized that she seems to have lost so much weight."

And parents of Duff fans sound concerned that their kids will try to copy their idol's super-thin look. "I don't want my kids to look at her and feel they have to become skin and bones to be popular. Teenagers often fall into the whole weight-control thing with disastrous results," worries one fan's mom. L.A.-based psychologist Dr. Robert Butterworth agrees. After looking at photos of Duff, he says the 5'4" actress looks thin. "For a lot of young people, [being thin] is considered normal," says Dr. Butterworth. "To me, that's the scary part. She may unwittingly help encourage others to do the same."

Hilary's reps insist that she's healthy and she took off the pounds by cutting out junk food.