John Goodman once weighed 392lbs (28 stone) before embarking on a healthy living journey which saw him drop a whopping 200lbs (14.3 stone).
The 70-year-old actor, who is well-known for his role as Fred Flintstone, amazed fans with his much-slimmer appearance at the Monte Carlo TV Festival on Sunday as he showed off his weight loss results.
John looked very stylish wearing a fitted suit jacket which he paired with beige trousers and a yellow tie.
He vowed to completely transform his life back in 2007 and his first step was giving up alcohol.
John admitted that he had began approaching 400lbs (28.6 stone) on the scale and knew he had to take drastic action to change his life.
By 2015, the Hollywood star managed to shed an impressive 100lbs (7.1 stone) and he then employed celebrity personal trainer Mackie Shilstone to take his weight loss even further.
John was introduced to a "Mediterranean-style eating plan", which involves focusing on a diet of fish, nuts, olive oil, vegetables and fruit.
John also works out six days a week, making sure to take 10,000 to 12,000 steps a day. His workouts tend to focus on using the elliptical bicycle or the treadmill.
"This didn't happen overnight — it's been an ongoing process. There needs to be strategic planning," Mackie told The New York Post.
John also opened up about his weight loss to ABC in 2017, saying: "In the old days, I would take three months out, lose 60 or 70 pounds, and then reward myself with a six-pack or whatever and just go back to my old habits.
"This time I wanted to do it slowly. Move, exercise. I'm getting to the age where I can't afford to sit still anymore."
Despite his epic weight loss, John has admitted that it hasn't always been easy.
He confessed that during the Covid-19 pandemic, he became lazy with his exercise routine, revealing he "let everything go".
He said he still hasn't quite got back to his strict regime, but he is focused on improving his health once again.
Speaking to Rolling Stone, he said: "I haven't been exercising, but I'm going to start a routine again this summer where I can get some stuff done.
"I've just let everything go just because I haven't had the energy."
He explained how a lot of his routine simply relies on him taking his dogs for a walk. Prior to Covid, however, he had been a keen boxer for fitness.
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