The 37-year-old singer - whose real name is Stacey Ferguson - admits that reducing fruits and vegetables down to their liquid form is how she achieves her healthy look thanks to a suggestion from her husband Josh Duhamel, 39.
She told Shape magazine: ''Josh turned me on to the book The Beauty Detox Solution, by Kimberly Snyder. It's about juicing as a way of life. I don't plan to make the switch completely, but I'm adding superfoods to my system with her green smoothie.''
However the performer confessed that she still has craving for unhealthy fare.
She said: ''I'm famous for splurging at fast-food places. I'm currently obsessed with Taco Bell's bean and cheese burritos with extra green sauce and extra cheese. Gluttony!''
However exercise is one thing she will never get bored of thanks to her love of music.
She continued: ''I'm glad that our music motivates people to exercise. If I had to pick just one song to run to, it would be 'Violet' by Hole. It makes me want to run.''
Speaking about her routine, she added: ''I have to wear two sports bras when I do my cardio. It takes a lot to hold these puppies up!
''I switch up my workouts all the time. I'll go from jumping rope to hiking to the elliptical. I also use free weights and bands. It keeps me challenged and fends off boredom.''
Marmaduke is perhaps the world's most famous Great Dane, he was originally brought to life...
Planet Terror Trailer Robert Rodriguez, co-director of Sin City, brings you Planet Terror, a retro-futuristic...
Longtime buddies Quentin Tarantino and Robert Rodriguez have worked together before (Four Rooms, Sin City),...