"Carbs are our body's main source of energy and they fuel various functions not only having to do with physical activity but brain function and proper organ function as well," said Maggie Michalczyk, RD, a Chicago-based registered dietitian and ambassador of A Sweat Life, to POPSUGAR. "While we may think of them as something to limit (yes, refined carbs should be limited and replaced with whole grains and healthy carbs like those found in starchy vegetables, etc.!) our intestinal heath and waste elimination mechanism rely on them, too," she explained. Definitely don't ditch them entirely.