Demi Lovato is revealing her secret weapon when it comes to staying healthy.

In an Instagram post, the "Really Don't Care" singer introduced her fans to her personal trainer Ronny Comacho, whom she praises for helping her get into the best shape of her life and live a healthier lifestyle.

"For the past 8 months this man has helped me beat my hardest critic: myself. The first day he gave me my meals, that him and his wife cook themselves, he looked me in the eyes and said 'We are going to kick this eating disorder's ass!!!'" Lovato wrote. "He was as determined as I was and has been a huge part of my recovery ever since. I've never been happier and healthier and I credit so much of that to this man and his beautiful wife."

In a photo collage, the singer and actress showed off her notebook with her workout plans and records, motivational messages written on her mirror and a selfie with Comacho.

"Thank you Ronny & Elise Comacho for staying up so late to cook my meals and getting up so early to help transform my body but most importantly my mind," she continued. "You both have truly changed my life. Now everyone.. go check out his website!!! www.uevolve.fitness!! (P.S. Every circle on the notebook is a new personal record... Yay!!!) #AustraliaHereICome #AsiaAreYouReady?! #Philippians4:13 #9AMSunday #NOchella (because while others are partying.. You're getting ahead..)"

Lovato has battled bulimia and spent time in a rehab center for "physical and emotional issues." The singer also admitted to "self-medicating" with drugs and alcohol.

The former Disney darling recently celebrated three years of sobriety. Lovato thanked her long-time boyfriend Wilmer Valderrama, whom she credited for helping her recovery from drug and alcohol addiction.

"I wish I could put into words how grateful I am for this man right here. But my love has grown to a level that words could never possibly express how much this man completes me. He's loved me the way I never thought I deserved to be loved and with this day marking my 3rd year sober," she captioned a romantic pic of her and her beau sharing a kiss.

"After sharing my ups, putting up with my downs and supporting my recovery... he still never takes credit and I want the world to know how incredible his soul is. I really wouldn't be alive today without him. I love you Wilmer."