Liam Hemsworth was forced to quit his vegan diet after suffering with kidney stones.

The 30-year-old actor followed a plant-based diet for almost four years until February 2019, when he was forced to switch up his eating habits after enduring ''one of the most painful weeks'' of his life during a battle with kidney stones.

Recalling his health battle, he said: ''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. I was doing press for 'Isn't It Romantic'. But I had to go to the hospital and get surgery. It's all good now, thankfully. But 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.''

Liam's particular kidney stone was caused by the high amount of oxalate - a natural substance found in vegetables - in his diet, and so he had to ''completely rethink'' what he eating in order to get his health back on track.

He added: ''Well, my particular kidney stone was a calciumoxalate kidney stone. It forms from having too much oxalate in your diet. Oxalates are really high in a lot of vegetables, specifically spinach, almonds, beetroot, potatoes. 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.''

The 'Hunger Games' star says ''health'' is what inspired him to try a vegan diet in the first place, and whilst he ''felt great'' to begin with, he has since ''reassessed'' his diet to make a meal plan that works for his body.

Speaking to Men's Health magazine, he said: ''Health for sure. I go from one extreme to the other. My mum always makes fun of me. She's like, 'If you could just find a happy medium in between all these things you do, then you'd probably be better off.'

''It was right before I started shooting 'Independence Day: Resurgence'. The first two years, I felt great. My body was strong, my cardio was high. What I say to everyone is 'Look, you can read whatever you want to read. But you have to experience it for yourself. You have to figure out what works best for your body.' And 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.''