Can you really change your metabolism? - Chew On This - MSNBC.com

"You should also get pleasure from eating. Even if adding a piece of dark chocolate is your wish, go for it, one square at a time, as it aids in happy brain chemistry and adds a natural bitter which aids digestion. Improving digestion this way also strengthens the liver, kidneys and lungs, all which facilitate a healthier metabolism."
This article has great advice about managing your metabolism...