Singer, actress, and former Nickelodeon star Victoria Justice stars on the cover of Health [1] magazine's November issue, glowing and toned. The 22-year-old opens up in an interview [2] about being diagnosed with Hashimoto's disease, an autoimmune disorder, and how its affected her diet, weight, and self-confidence. Read ahead for quotes from Victoria on her favorite workouts and ways she stays balanced.

• On her struggles with Hashimoto's disease: "A few years ago, I was diagnosed with Hashimoto's, which is a thyroid autoimmune disorder. . . . This Korean acupuncturist put me on a super-strict diet, where I was a pescatarian…. I also couldn't eat any sugar, wheat or dairy. . . .They had put me on this thyroid medication, and I think the levels were too high for me because it caused my skin to break out. . . .Also, at first, I was losing a lot of weight, then I went on tour and I started gaining weight, and it was the most I'd ever gained in my life. I was, like, 115 pounds. Then when I filmed a movie last summer, I actually went under 100 pounds. It was crazy, but things have leveled out, and I'm back to normal."
• On her self-confidence: "It definitely did affect my confidence, and it made me a little bit more self-conscious. But at the end of the day, I had the support of my family and friends. I knew that the people around me had my back. Now I really empathize with people who have issues with their skin, because it can get you down."
• On her workouts: "I love taking classes to switch it up, so I'll do a dancing class or a twerk class…. It's actually a really great workout. After 10 minutes of twerking, your thighs and your butt feel it right away. [Laughs] But it's so much fun. You feel free. It's like, 'Who cares? I'm twerking!'"
• On how she stays centered: "I try to meditate every day. It's important to take that time, even if it's just 10 minutes, to block everything out and get grounded again. And I love to lie on my hammock and read things that are inspirational and motivational, whether it's a self-help book or an autobiography."