1. Your metabolism
It’s no wonder metabolism is a subject of fascination and speculation: The process that turns food into fuel powers all that we do. “Even when you’re sleeping, your body requires energy for things like breathing and repairing cell damage,” says Donald Hensrud, MD, medical director of the Mayo Clinic Healthy Living Program. The number of calories you need to perform such basic functions is called your resting metabolic rate (RMR)—and it can affect everything from your waistline to your energy level. Read on to learn how to keep your metabolism revved so your body is operating at just the right speed.