Jonah Hill's weight loss journey: How the actor, 42, took life-changing steps to drop 12 stone as fans are left shocked by his 'unrecognisable' appearance in new show Outcome

He has long been open about his struggles with weight loss, having reportedly weighed around 375 pounds at his heaviest.

And Jonah Hill left fans shocked by his 'unrecognisable' appearance in the first look at his upcoming film, Outcome. 

The actor, 42, showed off his slimmed-down figure in a snap taken with his co-star, Keanu Reeves, who portrays Hollywood icon Reef Hawk opposite Jonah's crisis lawyer, Ira.

In the snap, Jonah donned a bald head and a bushy grey beard, which was a stark contrast to his usual curly brown locks and brown beard.

The film premieres on Apple TV on April 10, and the actor made a rare red carpet appearance on Tuesday to promote the new black comedy.

For the occasion, he continued to show off his impressive weight loss in baggy jeans and a dark sweater.

Outcome features Keanu as a Hollywood star named Reef who embarks on a journey of redemption after a mysterious video that threatens to cancel him emerges.

Jonah has undergone a major transformation in recent years, with exercise scientist and nutritionist Amelia Phillips estimating he has lost nearly 200 pounds, as reported by HELLO!

The actor, who is best known for his roles in Superbad and 21 Jump Street, has been open in the past about his fitness and wellness journey.

He candidly shared how he had battled body issues since his teen years, in a piece he wrote in his magazine Inner Child back in 2018.

The Moneyball star admitted he spent most of his young adult life being called 'gross and unattractive', adding: 'I really believe everyone has a snapshot of themselves from a time when they were young that they’re ashamed of.

'For me, it’s that 14-year-old overweight and unattractive kid who felt ugly to the world, who listened to hip-hop and who wanted so badly to be accepted by this community of skaters.'

After speaking to a nutritionist and adjusting his diet, Jonah went on to lose 40 pounds.

He told ABC News in 2012: 'I wish there was some crazy thing I did, like a pill or a genie, but I went to see a nutritionist, and he told me what to eat to change my habits. I found that Japanese food was very helpful to me.'

The star also started running to ease himself into exercise. Appearing on Kidd Kraddick's radio show he said he 'started physically running instead of emotionally running' as well as doing push ups.

After beginning with just ten push ups a day he eventually worked his way up to 100 reps per day.

The star admitted he struggled to cut out beer, confessing a pint is his 'Achilles heel'.

Jonah has also been vocal about how his weight was linked to his identity as a comedic actor despite how important it was for his career and health to not be so big.

Speaking to Vulture in 2011 after losing 40 pounds, he said: 'Being healthier came along with maturity and it's hard because a lot of times people want you to be the guy you were when they met you.

'And I love doing funny movies but I want to mature, literally, in how I treat myself. I'm not living in a frat house with a bong plastered to the table.

'But all this stuff [points to his body] is just part of maturing in body and in mind. I just want to be a good man and to make my family proud. And, you know, I want to live a long time.'

However, in 2016 the actor gained the weight back to play arms dealer Efraim Diveroli in War Dogs alongside Bradley Cooper and Miles Teller. 

Once the film was released, Jonah turned to pal Channing Tatum to ask how best to shed the weight once again. 

Speaking candidly on the Tonight Show he told Jimmy Fallon a year later: 'I wanted to get in better shape, so I called Channing Tatum and said, "Hey, if I eat less and go to a trainer, will I get in good shape?"

'[He said] 'Yes, you dumb mother****er, of course you will. It's the simplest thing in the entire world".'

Jonah then began boxing to stay in shape after he was seen in snaps jabbing and shadow boxing with a personal trainer.

 Back in 2021, Jonah spoke up about body positivity and struggling with his body image over the years in a now deleted post. 

'I don’t think I ever took my shirt off in a pool until I was in my mid 30s even in front of family and friends,' he wrote on Instagram. 

'Probably would have happened sooner if my childhood insecurities weren’t exacerbated by years of public mockery about my body by press and interviewers.'

He continued: 'I’m 37 and finally love and accept myself.'

The star went on to say his message was for 'the kids who don’t take their shirt off at the pool'.

'Have fun. You’re wonderful and awesome and perfect. All my love,' he concluded.

In 2023, the star discussed his fluctuating weight with his therapist Phil Stutz for his second feature directorial effort, the Netflix documentary Stutz.

'When I was a kid, exercise and diet was framed to me as like, "There's something wrong with how you look,"' the Winning Time director recalled.

'But never once was exercise and diet propositioned to me in terms of mental health. I just wish that was presented to people differently.'

Jonah admitted growing up overweight 'intensely f***ed me up,' and inside he still feels like 'a 14-year-old boy who's very overweight and has acne and feels very undesirable to the world.'

'​​Inherently, at my core, I'm still this unlovable person,' he explained.

'But the work is inching toward [realising] that it's great to be this person. But that's still very hard.'