Miley Cyrus leaves pilates in West Hollywood, CA. Credit: Oliver S Wolf/Splash News Online

Miley Cyrus is thinner than ever, but not because she suffers from an eating disorder.

On Sunday, the 19-year-old LOL actress slammed rumors she's starving herself, tweeting: "For everyone calling me anorexic, I have a gluten and lactose allergy. It's not about weight -- it's about health. Gluten is crap anyway!"

Cyrus then told one fan: "Everyone should try no gluten for a week! The change in your skin, physical and mental health is amazing. You won't go back!"

The "Can't Be Tamed" singer's tiny frame isn't from diet alone; she also takes Pilates classes in West Hollywood several times a week.

Rumors about her health aside, Cyrus is happier than ever thanks to Liam Hemsworth, whom she began dating in 2009.

How do they keep the spark alive? "I try to be romantic," Hemsworth once told Us Weekly of his on-and-off love. "I surprise her with some flowers or a gift, or take her out to dinner."