Jack, who split from Dani last month, has taken to his socials to show off his weight-loss, after taking part in Protein World's Slender Plan. He wrote, 'Summer come at me 😎 thanks @proteinworld for supporting me in getting in better shape. Couldn’t recommend the slender plan enough. I feel physically and mentally stronger and the journey has only just begun 🥊 🥊 so keep your eyes peeled 🥊🥊 and no I never had a spray tan I had just got back from ibiza'. [sic]
According to reports, Jack lost the weight in just three months, after doctors told him he was 'clinically obese' for his 5ft 11 height.
The popular reality star shredded 11cm from his waist and 42% body fat. Impressive!
The amazing transformation comes just weeks after Jack announced he'd split from Love Island co-star Dani Dyer, despite the pair living together.
He wrote on Instagram at the time, "There is no easy way to say this and it isn't going to be an easy time but me and Dani are not in a relationship anymore.
"We will always care a lot for each other and I mean that from the bottom of my heart and I wish her nothing but happiness.
"We have some amazing memories together and have been through a lot but sometimes things just aren't meant to be and we really did try and make it work but unfortunately didn't and that is life. That's all I have to say, a break up is hard enough as it is for both of us let alone in the public eye so I hope everyone is considerate and understands this. X"
Check out which Love Island couples are still together, and which aren't:
love island couples heat slider
Hannah Elizabeth and Jonathan Clark (2015): SPLIT
Remember when they, like, got engaged on the show? That one didn't quite last...
Katie Salmon and Adam Maxwell (2016): SPLIT
Adam claimed he was '100 percent single' shortly after leaving the villa and, um, that was that. #Kadam; gone but never forgotten.
Gabby Allen and Marcel Somerville (2017): SPLIT
Gabby dumped Marcel after he was spotted cheating as they holidayed TOGETHER. Blimey.
Scott Thomas and Kady McDermott (2016): SPLIT
Scott and Kady managed a year before splitting in 2017.
Nathan Massey and Cara de da Hoyde (2016): STILL TOGETHER
They've got their little Love Island baby and everything.
Jamie Jewitt and Camilla Thurlow (2017): STILL TOGETHER
An absolute success story of Love Island 2017, Jamie and Camilla and Jamie are still the CUTEST of couples.
Sam Gowland and Georgia Harrison (2017): SPLIT
Sam seems to be doing alright for himself on Geordie Shore, so we don't think he's too gutted.
Olivia Attwood and Chris Hughes (2017): SPLIT
The couple were plagued with cheating rumours throughout their relationship (who can forget that whole Chris Hughes and Katie Price debacle?). Since their ITVBe show Crackin' On ended, Olivia's confirmed she's back with ex-boyfriend Bradley Dack.
Malin Andersson and Terry Walsh (2016): SPLIT
He did date fellow Love Island-er Emma-Jane Woodhams eight months in actual real life before calling it a day. AH WELL.
Rykard Jenkins and Rachel Fenton (2016): SPLIT
At least they lasted 18 months. Not bad going...
Jessica Hayes and Max Morley (2015): SPLIT
Still fancy Max in a huge way, not gonna lie.
Alex Bowen and Olivia Buckland (2016): MARRIED
Alex and Olivia are married and literally as strong as ever. We like to live vicariously through them, to be honest.
Jordan Ring and Zoe Brown (2015): SPLIT
Absolutely DID NOT work IRL. Neeext.
Luis Morrison and Cally Jane Beech (2015): SPLIT
They had the first ever Love Island baby, but things later took a sour turn, with Cally accusing Luis of 'cheating' on her whilst she was pregnant with their daughter. (Oh dear).
Tyla Carr and Jonny Mitchell (2017): SPLIT
Oh it was never gonna last, was it?
Kem Cetinay and Amber Davies (2017): SPLIT
The Love Island 2017 winners split in December 2017; five months after the finale.
Montana Brown and Alex Beattie (2017): SPLIT
These two split just weeks after returning to the UK. Sad times.
Dom Lever and Jess Shears (2017): MARRIE
Jess and Dom are so together, in fact, they got 'married' on Good Morning Britain on Valentine's Day 2017. They then got, y'know, properly married.
Sam Bird and Georgia Steel: SPLIT
You know how this one went. Sam accused Georgia of cheating on him with her ex, which she denied. It's safe to say they didn't split on the best of terms.
Zara McDermott and Adam Collard: SPLIT
Zara and Adam have called it quits. WAH.
Megan Barton-Hanson and Wes Nelson: SPLIT
Megan and Wes did move in together, but announced their split in January 2019 following rumours Wes was getting close to Dancing on Ice partner Vanessa Bauer. Uh oh.
Josh Denzel and Kaz Crossley: SPLIT
Josh and Kaz announced their split in February 2019, with Kaz saying: "Sometimes things don't go the way you planned, but you have to be grateful for the journey. Thank you for everything especially showing me how to love myself again."
Samira Mighty and Frankie Foster: SPLIT
Frankie reportedly cheated on Samira and that was that. Done. Over. thank u, next.
Laura Anderson and Paul Knops: SPLIT
There's no bad blood between Laura and Paul, but they split months after making it to the final of the show.
Jack Fincham and Dani Dyer: SPLIT
Although they briefly split in 2018, in April 2019, Jack Fincham announced he was no longer in a relationship with Dani, just hours before her book launch. (OUCH).
Meanwhile, if you can't wait for the brand new series of Love Island, check out everything you need to know about Love Island 2019 right here.
NOW WATCH: Dani Dyer becomes your an Agony Aunt!
If you’re a sucker for the Spice Girls and love a bit of One Direction, you need heat Radio in your life. We’re online at heatradio.com. You can still get us on the free app on your Android, iPhone or tablet. Tune in on Freeview channel 716 on the telly or get us on your smart speaker by asking it to "play heat radio."