She recently launched her own health and fitness website, giving fans tips on how to get her incredibly toned figure.
But Lucy Mecklenburgh's dedication to stay in shape appears to have taken its toll on the reality star, who showed off her slimmed-down shape in a white bikini as she joined the TOWIE gang in Marbella on Thursday.
Scroll down for video
Slimmed down: Lucy Mecklenburgh displayed her noticeably more slender figure as she wore a plunging white swimsuit while holidaying in Marbella on Thursday
White hot: Lucy teamed the one-piece with a pair of towering heels to make her legs look even longer
Pert: Lucy showed off her tiny waist and her enviably long legs in the swimsuit
The 21-year-old star looked significantly more slender than she has in recent years' trips to Marbs, displaying her tiny waist and pert derriere in the plunging white one-piece.
Lucy made her legs look even longer in a pair of towering wedge heels, carrying a Louis Vuitton bag as she strolled down to the beach to surprise her fellow TOWIE stars.
The pretty brunette left her hair loose in beachy waves and went make-up free but for a slick of lip gloss on the outing.
Careful! Lucy looked light she came close to taking a tumble as she stolled along in a pair of sky high wedges
Working out: Lucy's slender figure is down to her regular workouts and her new fitness video suscription service, Results With Lucy
Strutting her stuff: Lucy certainly knows how to flaunt her best angles
Careful! Lucy had to concentrate to ensure she didn't trip up on the stairs in her heels
Lucy is enjoying the trip to Marbella as a single woman, following her split from former fiancé Mario Falcone.
Perhaps the star has been on the heartbreak diet but, combined with her daily workouts, she has lost a significant amount of weight.
And her relationship breakdown won't have been made any easier by the fact that Mario, who Lucy discovered had been sending flirty messages to another girl and asking to take her out within days of their split, is also in Spain - and was seen surrounded by a host of bikini-clad women as he soaked up the sunshine.
Talking through the scenes: Lucy was seen chatting to production staff as she took a break from filming
As she was: Lucy looked significantly more curvy when she holidayed in Marbella back in 2011
From full to pert: Lucy's derriere also looks noticeably smaller than her 2011 holiday
But while Mario has been keeping a somewhat low profile since the split, Lucy is doing her utmost to move her life in a positive direction.
The star was recently seen making an incongruous appearance at the Cannes Film Festival, where she is said to have met with film director Will Holman about the prospect of starring in a horror film.
A source told The Sun: 'She is keeping tight-lipped about it but apparently the director loves her look and thinks she is the perfect female for an important character in his film.
Living the high life: Lucy's former fiancé Mario Falcone is also in Marbella, and was seen surrounded by bikini-clad woman as he soaked up the sunshine
Let the battle commence! Lauren Pope, Jasmin Wallia and Abi Clarke are among the other TOWIE stars who have been showing off their bikini bodies in Marbs
Under wraps: Gemma Collins wore a cover-up over her swimsuit as she arrived at the pool on Friday
Kicking back: Gemma later took off the kaftan to reveal a snakeskin swimsuit
'He’s sending her the script and intends to fly her out to LA for an audition and to get her on tape. He says Lucy has exactly the look of the character that he imagined in his own head.'
In addition to her movie ambitions, Lucy has also launched her own fitness site, Results With Lucy.
Hey Miss DJ: Lauren Pope works the decks at the Sisu Hotel pool party and happily poses with her headphones on
Revealing: Lauren's TOWIE co-star Dan Osborne didn't seem to mind her racy top which showed off her bikini beneath
The subscription service gives viewers the chance to work out alongside Lucy and her personal trainer Cecilia in a series of videos, with the website saying: 'Learn her exercise routines and train along, using the most up to date fitness techniques.'
A YouTube video promoting the subscription service was released on Friday, with Lucy seen working up a sweat with some hula hooping, sit-ups and burpees.
Fancy seeing you here! Chelsee Healy also attended the bash at Sisu beach club and wore an interesting monochrome swimsuit and denim shorts
Read more: http://www.dailymail.co.uk/tvshowbiz/article-2330166/Lucy-Mecklenburgh-displays-slimmed-figure-plunging-white-swimsuit-joins-TOWIE-gang-Marbs.html#ixzz2UCKrAoEI