Hollywood insiders are commenting on the ever-growing number of young stars practically throwing themselves under the knife. While the famous persons on this list are all very different (some are famous for being really attractive singers, some are famous for being really attractive actresses, and some are famous for nothing but being really attractive) they all have two major things in common: they're 25 years old or younger, and have already seen the inside of a cosmetic MD's office.

Britney Spears, 25
Somewhere in the recesses of your memory, you can recall a time when Britney Spears was actually good looking. Before she met K.Fed and before she was the Promise Treatment Center's most famous inpatient, Ms. Spears had a smokin' hot body. 1999 was a good year for Brit - chart-topping success, a cute boy band boyfriend, and perky new breast implants to boot! Ah, yes, the year before the millennium was also the one in which she opted (at sixteen) for a bigger, more voluptuous chest. Anyone who caught the Kids Choice Awards around that time knows what I'm talking about, as she graced the stage in a sheer, white tank and ignited speculation concerning her overnight growth spurt. Although it was never confirmed, the size discrepancy (experts estimate she advanced from an A to large C cup in mere days) has since been recognized as truth. However, Spears would pay another visit to the plastic surgeon nine years later, this time at the ripe old age of twenty-five. As reported by CelebritySmack on April 9th, 2007, for the second go-round, she decided to stop by a Las Vegas LipoDissolve clinic for some pretty invasive fat melting injections (allegedly on her tummy, butt and thighs.) What better way to prepare for a comeback!

Mary-Kate and Ashley Olsen, 20
Remember when seeing the Olsen twins wearing cute, little matching outfits was enough to turn your stomach? Well, now the child stars have taken it a step farther. According to the HollywoodRag, Mary-Kate and Ashley are allegedly planning to have matching nose jobs, having already consulted the doctor who performed Jennifer Aniston's rhinoplasty, Beverly Hills plastic surgeon Dr. Raj Kanodia.

"A source told "In Touch Weekly" magazine: 'They both love changing their looks. They thought this would make them look more polished.'" By the looks up their earlier photos, many speculate this won't be the first nose job for either of the twins.

Keira Knightley, 22
As reported by FemaleFirst.co.uk, 22-year-old "Keira Knightley has blasted reports that she had collagen injections in her lips. The stunning 'Pirates of the Carribbean' star revealed that no-one believes her denials about being cosmetically enhanced.
According to the website, "She said: 'I haven't had my lips done. Can I just say that I haven't. It's the idea people believe it! I've had friends phone me up and I've told them 'Get Lost! Of course I haven't.'"

Strange, considering on March 19, 2006, the HollywoodRag claims, "Keira Knightley admitted to increasing the size of her top lip: 'I had a larger top line done.'" You be the judge.

Kellie Pickler, 20
I certainly voted for Season 5 American Idol contestant Kellie Pickler last year, when, on national television, she not only mispronounced the word "salmon," but claimed not knowing its meaning. Yes, it was a Jessica Simpson-esque flub that earned her a loyal following, a record deal, and a song performance on this season's American Idol to promote her new single, "I wonder." But alas, the sweet, naive, 20-year-old North Carolina native did not look like the girl most of us cried for last year, when she told all of America that her Daddy was in prison and her mama had run off. Yes, lots has changed for Kellie Pickler. Her new album "Small Town Girl" went gold on January 17th, 2007, despite the fact that Pickler's new look proves there's nothing really "small" about her these days. Host Ryan Seacrest hit the mark while interviewing Pickler after her most recent live performance on the show. While struggling not to gaze down into her new eye-popping cleavage, he asked her what she's been spending her money on lately. Kellie's response: "Just shoes." If that's truly the case, I'd say Kellie needs to fire her personal shopper!

Lindsay Lohan, 20
Poor Lindsay. She's grown up - and OUT - so fast since her big movie debut, where she played a set of identical twins in the 1998 remake of "The Parent Trap." Born in 1986, she was only twelve at the time. Rumor has it, she underwent the knife for these other "twins" when she was only seventeen. Thankfully, according to celebritycosmeticsurgery.blogspot.com, Lindsay has undergone a second breast augmentation procedure since this photo was taken, seeking a more "natural" look. Sheesh! I would hope so unless she's looking to star in a different type of adult film.

Nicole Ritchie, 25
When you think of Nicole Ritchie, your mind isn't immediately redirected to large breasts. The skin-and-bones TV star apparently wants to keep it that way, and is being very hush-hush about the breast enlargement she underwent recently. As reported by ivillage Entertainment, Richie is eager to distance herself from anorexia rumors, and has been trying to gain weight and fill out for paparazzi and her new curve loving boyfriend, Joel Madden. The twenty-five year old, even at her heaviest (normal) weight, was naturally flat chested, so these new pics showcasing considerable cleavage have fans scratching their heads. "Not only has The ENQUIRER confirmed Nicole's breast augmentation with a well-placed source," ivillage writes, "but a leading doctor who examined photos of her agrees there is no doubt what's behind Nicole's sudden growth spurt." Perhaps all the money she saved not buying food for the last three years is the culprit? Or maybe she sold her soul to the Devil (Paris Hilton) and magically woke up with them? I believe it.

Beyonce Knowles, 25
With gorgeous almond-shaped eyes and a luscious full pout, Beyonce Knowles wowed audiences last winter in the Academy Award winning "Dream Girls." Although Knowles is recognized within the entertainment industry as having one of the most beautiful and flawless faces around, her looks have certainly changed a bit since her early days with Destiny's Child. As reported by CelebrityPlastics.com, after having "her hair dyed and straighted, her lips redused and her nose narrowed [Beyonce] looks more like a Barbie doll, than an Black RNB singer." Why the extreme makeover? CelebrityPlastics.com blames Hollywood. "Pretty much without exception," the website writes, "a white aesthetic dominates the entertainment industry and cosmetic surgery business."

Heidi Montag, 20
If you don't know who Heidi Montag is, you're certainly not alone. She's never done anything other than look relatively cute and cause needless, incessant drama on MTV's reality show, "The Hills". Perhaps sensing her talent - or lack thereof - was never going to place her in the spotlight, many speculate that Montag sought out plastic surgery to help, ahem, boost her career. As reported in the May 7, 2007 issue of "In Touch Weekly," "Heidi initially backed out of her first appointment on March 20 because she didn't think it was a good message to send to her fans. But the 20-year-old finally took the plunge on April 2. She got breast augmentation from Beverly Hills plastic surgeon Dr. Frank Ryan to transform her small cleavage into a sexy C cup." According to TheHollywoodGossip.com, Heidi "had been contemplating the procedure for several years." "Several years"? The girl is twenty! Was she nine when she made this decision!

Ashlee Simpson, 22
Who doesn't know about Ashlee Simpson's nose job? Last year, when asked about the widespread speculation in the tabloids, the 22-year-old singer "giggled and told the Associated Press: 'Everybody's already saying it, so I just don't talk about it. I'm like, okay, whatever. It doesn't bother me.'" It did, however, bother Marie Claire magazine, and ignited heated criticism from thousands of Simpson's fans.

The July 2006 edition of Marie Claire featured a pre-nose job Simpson saying, "Everyone is made differently, and that's what makes us beautiful and unique. I want girls to look in the mirror and feel confident."

As reported by ChinaDaily.com, the editor of Marie Claire, Joanne Coles, fired back in the September 2006 issue when she wrote, "We're dazed and confused - and disappointed - by her choice, too." The magazine received thousands of letters from readers who agreed.

Ivanka Trump, 25
Will someone please explain to me why Ivanka's right implant is trying to devour her shoulder? Damn! Currently Vice President of Real Estate Development and Acquisitions at the Trump Organization, I think it's pretty clear what type of attention Ivanka Trump (daughter of Ivana and The Donald) hopes to get from her underlings. Yep. Apparently, the old phrase Less is More doesn't apply when your father's net worth is roughly 2.9 billion!