If you needed more proof that Zac Efron has officially left the weedy teenager of High School Musical behind to become a bona-fide buff babe, you've got it. Pictured on the set of his latest film, Bad Grandpa, Efron still managed to make us swoon despite wearing nothing but nude pants and a stuffed bumble bee. This got FEMAIL thinking about how many child stars have grown into stunning adults, and how many haven't... Haven't you grown: We got a sneak peek at Zac Efron's hot bod as well as his new film, Bad Grandpa, on Tuesday. He's come along way since his High School Musical days... It seems like only yesterday that Zac Efron's baby blues peeped out at from beneath his sweeping fringe as he serenaded us in High School Musical. But at the age of just 19, and playing a 16 year old, it felt rather creepy having a schoolgirl crush on the young star. So now he's 27 we are more than happy to be able to perve over his bulging biceps, hard six pack and toned legs... At first, Zac appeared to be among the few male child stars who have blossomed as adults, with the girls ruling the 'I was cute and now I'm hot' world. The obvious exceptions are Ryan Gosling - is there a hot list he isn't on? - and Justin Timberlake. Both were in the Mickey Mouse Club, along with Britney Spears and Christina Aguilera, plus Gosling starred as Young Hercules in a TV series of the same name at the age of 18. Always a handsome lad, Ryan Gosling went from a blond 'young Hercules' to appearing on every hot list ever . Justin has sorted his hair, got rid of those awful earrings and, how do we say this - grown into his face . After digging a little deeper, however, we remembered Slater from Saved by the Bell, aka Mario Lopez, whose dimples have dazzled for decades. Also Joseph Gordon-Levitt who surprised us all when he grew from being the long-haired awkward boy in Third Rock from the Sun into a suave-looking gent who knows how to work a suit. Then there's Taylor Lautner, who has such a baby face we still consider him to be a youngster, but at the grand old age of 23 and with some manly facial hair, he's now made it onto our list. Joseph Gordon-Levitt has grown from being the long-haired awkward boy into a suave-looking gent . Slater from Saved by the Bell, aka Mario Lopez, has dimples that have dazzled for decades . Taylor Lautner still has a baby face after all these years, but his new manly facial hair has got him on our list . Many cute-as-a-button boys, however, failed to grow into the hunks they could have been. Macaulay Culkin won our hearts as the mischievous young Kevin in the Home Alone trilogy, but somehow evolved into a greasy guy who looks, well, a bit weird... Ed Furlong was a heartthrob for youngsters brave enough to watch the second Terminator film. He was awarded Saturn and MTV Movie Awards for his part, and went on to appear in American History X and Pecker, but his career took a dive due to multiple arrests, alcoholism and substance abuse. Macaulay Culkin won our hearts as the mischievous young Kevin in the Home Alone trilogy, but somehow evolved into a greasy guy who looks, well, a bit weird... Ed Furlong was a heartthrob for youngsters brave enough to watch the second Terminator film, but his career took a dive due to multiple arrests, alcoholism and substance abuse . The gorgeous girls, on the other hand, have blossomed from sugar and spice to all things nice. We still see that six-year-old cutie from ET when we look at the now 40-year-old Drew Barrymore. She definitely had a few dodgy years in the middle, but now she's a boho babe that everybody loves. Dakota Fanning, too, started acting at the age of six, playing Ally McBeal aged five in the eponymous TV series. We still see that six-year-old cutie from ET when we look at the now 40-year-old Drew Barrymore . Dakota Fanning was the youngest ever nominee for a Screen Actors Guild Award when she was up for her role in I am Sam at age seven. She's still flexing her acting talents at the age of 21 . She was even the youngest ever nominee for a Screen Actors Guild Award when she was up for her role in I am Sam at age seven. Now the 21-year-old blonde bombshell is in anything and everything, from doing voice-overs to co-starring in the Twilight saga. Talking of which, Kristen Stewart was far from her mysterious, porcelain-skinned Twilight character when she appeared aged 12 in Panic Room, alongside fellow former child star Jodie Foster. Kristen Stewart was far from her mysterious, porcelain-skinned Twilight character when she appeared aged 12 in Panic Room . Sticking to the vampire theme, Anna Paquin, who plays Sookie in True Blood, won the 1993 Academy Award for Best Supporting Actress at the age of 11 for her role in The Piano. Now lusted after by everyone from vampires to werewolves, there must be something in Anna Paquin's blood... Meanwhile, Harry Potter must have waved his magic wand at Hermione (no that's not a euphemism), as Emma Watson grew from a pretty pixie into, well, a pretty pixie. But one with serious sass, style and sex appeal. Anna Paquin won an Oscar at the age of just seven, but she's more likely to win style awards today... Emma Watson has grown from a pretty pixie into, well, a pretty pixie. But one with style and sex appeal . Then of course there are the teeny boppers of the Noughties, with the two big ones, Hilary Duff and Miley Cyrus, showing exactly how to - and how not to - deal with fame at a young age. While Duff kept her image clean after rising to fame as a singer and actress in Lizzie McGuire - although admittedly we're not 100% sure on her green/grey hair just yet - Cyrus has caused controversy after controversy since her Hannah Montana days. She's doing a great job of shirking her squeaky clean teen image, from twerking on stage to writhing around naked on a wrecking ball. As for the boys? We'll do the male species a favour by not taking a look at Justin Bieber... Duff kept her image clean after rising to fame as a singer and actress in Lizzie McGuire - although admittedly we're not 100% sure on her green/grey hair just yet . Cyrus has caused controversy ever since her Hannah Montana days. She's doing a great job of shirking her squeaky clean teen image, from twerking on stage (pictured) to writhing around naked on a wrecking ball .
Efron's buff bod is far from the weedy teen days of High School Musical .
FEMAIL looks at more famous tots and teens all grown up and looking hot .
Cute kids don't guarantee cute adults, though, as we find out...