Negative calorie foods are foods that supposedly require more calories to digest than the amount of calories the foods themselves contain. Although there is no proof that negative calorie food diets make you lose weight, nutrition professionals say snacking on these foods, or using them to satisfy cravings, is a good idea...simply because they are healthy and low-cal. My personal favorite negative calorie foods are asparagus, broccoli, carrots, cauliflower, spinach, watermelon, honeydew, strawberries, apples, pineapple, peaches, cantaloupe and blueberries. And of course these foods are only negative calorie foods in their natural state, not when they're slathered in butter or canned in heavy syrup (Doy!). Experts agree that the best option for long-term weight loss success is to consume negative calorie foods as part of a balanced diet. And, of course, they also recommend exercise.