All calories are not created equal. Some require more energy to digest, giving you "a bigger bang for your buck," says dietician Leslie Bonci, director of sports nutrition at University of Pittsburgh Medical Center and an author of the upcoming book "The Active Calorie Diet." Some tips:
•Eat plenty of low-fat protein. Digesting these foods requires the most calorie burn. Just keep choices healthy: lean meats, eggs and low-fat dairy products, for example, not fatty cheeseburgers.