What many people probably don't know about Hollywood star Rob Lowe is that he was an alcoholic.
For the actor, who landed his first major TV role in 1979 and whose breakthrough came in the 1983 film T he Outsiders, it was revamping his lifestyle choices – ditching certain foods and beverages.
In fact, he hasn't touched alcohol for exactly 30 years, and there's a big reason why.
"I felt like in my 20s I probably enjoyed it a bit too much," Lowe told news.com.au in January.
"I learned that when I was not drinking, I liked who I was better as a person and then there's the added benefits of feeling and looking better."
The Golden Globe-winning actor who committed to sobriety on May 10, 1990, took to his Instagram on Sunday night to mark the milestone achievement.
"30 years ago today, I found a sober life of true happiness and fulfilment," Lowe wrote.
"I am filled with gratitude on this anniversary. From a treatment center (sic) in Arizona to a bomb shelter in Israel, I have come to know many extraordinary people, and the fellowship of recovery has changed my life and given me gifts beyond my selfish imaginings.
"If you, or someone you love is struggling with any kind of addiction, there is hope! Love to you all."
His post has been liked more than 100,000 times with hundreds of fans and relatives congratulating the actor on his inspiring achievement.
"30 years!!!!! I am so endlessly proud of you. And of @sheryllowejewelry for putting up with you!!" his son John commented.
"A fantastic inspiration. I hope those who need it see your story," a fan added.
After reaching idol status, Lowe was training with the UCLA track team around the same time his love of partying and alcohol became an addiction.
Known as one of the '80s Brat Pack, Lowe trained like crazy to reassure himself he didn't have a problem. But once he hit 26, he managed to get sober, with exercise playing a new role in his life as alcohol took a back seat.
"It became an outlet for all of the tension, stresses, compulsivity," he told Oprah Winfrey in 2014. "I funnelled the addiction, frankly, into that.
"I don't drink and haven't for 30 years now and that's such a competitive advantage for me – just the calories alone from booze are just brutal and it just kills you."
If you look back on his photos from his 30s, you will find that not much has changed — the 55-year-old is still a lean, fresh-faced man in peak physical condition.
He even said so himself, but in a more humbling way.
"I, 100 per cent feel better than I have ever felt," he recently told news.com.au, "and for me that started in my 40s and from then on until now I feel each year has been the best iteration of myself."
In his 20s Lowe became aware of what he was consuming; however, it was until he reached his 30s that his lifestyle changed completely.
"It's that moment when you wake up and realise, 'I can't eat like I used to' and that day comes for all of us."
Instead, he did something about it.
"Then you just have to make a choice with what you want in terms of quality of life, your energy and how you look and feel," Lowe said.
"You have to make some adjustments and that's what I did."
He began eating in the Atkins style (low-carb lifestyle) without knowing he was doing it.
The Atkins diet first devised in 1972 by Dr Robert Atkins but was made famous by his second book, Dr Atkins' New Diet Revolution, in 2002.
Since then the high-protein diet has gained plenty of attention with about three million people in the UK alone having tried it in 2003.
"I was probably in my mid 30s when I really cut the carbs, having very little pasta and bread and focusing more on proteins and the right fats – my new thing is trying to manage the sugars because I still have a sweet tooth," Lowe said.
While the diet has been criticised for advocating a drastically reduced carbohydrate intake – even being compared to the likes of the keto diet, a similar low-carb meal plan – Lowe says its flexibility continues to make it desirable.
"Atkins is the original keto, it's just more flexible," he says, admitting "keto is very hard to maintain".
"It's not all red meat, bacon and eggs, it's actually a more balanced approach. You're eating things like lean proteins and vegetables. You're eating foods high in fibre, you have your fats like olive oil, avocados and fruits.
"If it were a diet, I couldn't do it because it wouldn't be sustainable. It truly is a lifestyle, and I don't feel like I'm missing out on anything."
For a man in his mid-50s, Lowe said he had never felt better, with his new and improved lifestyle giving him a tremendous amount of energy.
If he's not on-set filming a movie or TV show, you will find Lowe either surfing, hiking, playing tennis, golf or on his peloton bike.
His style of training varies from interval exercises with weights to mixed cardio.
Food and fitness go hand-in-hand for the actor, who says if you are living life right, the older you get, at least spiritually and mentally, you should be feeling the best you have ever felt.