By: Kenlyn Young, LDN, MS, RD, Dietitian, Duke Integrative Medicine. Metabolism is so confusing and frustrating, right? Common questions asked, "Why can't I lose weight? Why is my metabolism so slow?" In simple terms, "Metabolism is the internal process by which your body expends energy and burns calories. It runs 24/7 to keep your body moving, even when resting or sleeping, ...