Liam Hemsworth had to change his plant-based diet for his own health! In a new interview for the May issue of Men's Health, which Hemsworth also features on the cover for, he opened up about the medical incident that forced him to rethink the way he was eating.

"I was vegan for almost four years, and then February of last year I was feeling lethargic. Then I got a kidney stone. It was one of the most painful weeks of my life," Hemsworth shared. He went on to reveal that the incident happened to occur while he was promoting his new movie. "I was doing press for Isn’t It Romantic. But I had to go to the hospital and get surgery," Hemsworth said.

RELATED CONTENT: Watch Liam Hemsworth And Christoph Waltz In New Trailer For Most Dangerous Game Here

Hemsworth had to re-evaluate his idea of "super healthy"

Hemsworth went on to say that while he's "all good now" post-surgery, he still had to make significant changes to his lifestyle. "Once you get one kidney stone, you have a 50 percent chance of getting another one if you continue eating the way you were eating," he explained. "Well, my particular kidney stone was a calciumoxalate kidney stone. It forms from having too much oxalate in your diet".

After finding out that information, Hemsworth realized that the diet he thought was keeping him fit and healthy was actually what had sent him to the hospital!

"Oxalates are really high in a lot of vegetables, specifically spinach, almonds, beetroot, potatoes," he said. "Every morning, I was having five handfuls of spinach and then almond milk, almond butter, and also some vegan protein in a smoothie. And that was what I considered super healthy. So I had to completely rethink what I was putting in my body".

RELATED CONTENT: Kim Kardashian Reveals Her Family Eats A Plant Based Diet North Pescatarian

Hemsworth advises doing "what works best for your body"

Hemsworth shared how he's prone to go from "one extreme to the other", which is what led him to following a vegan diet in the first place. He also acknowledges that while different kinds of diets and workouts can be advertised as being beneficial for your health, not everything will work for everyone. 

"You have to figure out what works best for your body," he said. "If something works well for a period, great, keep doing it. If something changes and you’re not feeling great, you’ve got to reassess it and then figure it out".

RELATED CONTENT: Harrison Ford Clean Diet Very Boring

He also talked about how working out has helped him stay grounded and healthy even while enduring all of the challenges of last year, which also saw his divorce from Miley Cyrus. "Honestly, the past six months…I’d say exercise and fitness is a big thing for me to just feel balanced and level headed," he told Men's Health.