For me, weight loss is about 80% what I'm putting in my mouth and about 20% exercise. That said, when I do Shred, I add another cardio workout to go with it. Sometimes I will go straight to the elliptical for an extra 20-30 minutes, sometimes, I do cardio later in the day.
I wear a heart rate monitor when I workout, I "need" to see at least 300 calories burned, I only burn 150-200 doing Shred.