Singer Demi Lovato arrives at the 58th Grammy Awards in Los Angeles, February 15, 2016. Demi Lovato has never shied away from talking about addiction and eating disorders, both of which she battled as a teen pop star before entering rehab. The 23-year-old pop star and mental health advocate spoke about her path from beauty pageants to television stardom and the body image issues that plagued her along the way, eventually leading the singer to alcohol and drug abuse. "But once I started eating again, the other issues got worse.