just a thought:
besides assisting in building muscle, protein can help speed up the metabolism because of it's high thermal effect. In other words, the body has to work hard to break down protein for digestion. This is a good thing.
The protein in bars and powders are broken down into an almost pre-digested form.
Therefore, the body doesnt getthe same thermal effect by breaking it down, because it is already broken down.
Point: try to get the protein thru regular diet by eating more fish and chicken.
Just some "food" for thought!