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.
•Focus on fiber. Fiber-rich foods place second on the active calorie scale. Load up fresh vegetables and fruits — with the skin on — beans, bran cereals and whole-wheat products, including breads.
•Go for chewy. Your mouth, the first stop in the digestive process, will have to work harder. Choose whole fruit versus fruit juice and toss extra beans or broccoli into soups and stir-fries.
•Add spice. Including items such as crushed peppers, wasabi and hot sauce at most meals likely will burn 10 to 20 extra calories a day thanks to a compound called capsaicin — not a lot, but it adds up over time. If you can't tolerate spice, try cinnamon, garlic, ginger or cloves and use vinegar as a marinade.
•Drink green tea. Hot or cold, take advantage of a metabolism-revving substance in tea leaves (just don't ruin it with lots of sugar). As for coffee: Caffeine, a central nervous stimulant, also can help torch a few calories.
•Cook more. Opening a package burns almost zero calories — much less than preparing meals from scratch.
•Beware nonactive calories. Cookies and pastries, chips, sodas and highly processed meats such as hot dogs and chicken nuggets are easily digested and most likely to be stored as fat.