YES! Water! Lots of it!
Check the ingredients for signs of the evil 6. I would be wary of artificial flavorings and coloring.
Don't starve yourself and don't let yourself down! You're probably losing fat and building muscle faster. (Muscle weighs more than fat.) I've been on Cardio Sculpt for about a month now, and I'm really starting to notice that my belly is starting to tighten up. Hang in there! I started eating Vegan almost a year ago, and the lack of animal fat caused me to lose about 20lbs, but it's a double edged sword. The fact that I am working with a lower variety of protein in my diet caused me to lose muscle content in my body. I can feel those muscles now that I've been working them lately. I started DB at 155 lbs, and I'm hovering at 151.6-ish. I hear you, but I'm going through it to.
Wow I don't know what it is, but this is the fifth time I've done kickin' it with Kiera as part of DB Sculpt, but I really felt it today. I guess I didn't have to think about keeping the core engaged through the work out, because I feel it now.