Negative-calorie foods--also known as calorie-burning or catabolic foods--are foods that supporters believe can help you lose weight by requiring more calories to digest than they provide to the body. These foods can be divided into two main categories: high-grade and low-grade. High-grade negative calorie foods have a high calorie-to-calories required to digest ratio. Proponents believe the key to weight loss is to center your diet primarily around the high-grade negative-calorie foods. However, many health professionals are skeptical about catabolic foods: MayoClinic.com reports that while certain foods are negative-calorie items, it contends that studies do not prove that eating these foods is an effective weight loss strategy.
All types of vegetables--from asparagus to endive to cucumbers to zucchini--are considered negative calorie foods, although some are considered high-grade while others are categorized as low-grade. High-grade negative calorie vegetables include sweet potatoes, celery, eggplant, all types of peppers, artichokes, parsley, leeks, spinach, different types of lettuce, carrots, Brussels sprouts, radishes and broccoli. The following are the most common low-grade calorie-burning vegetables: turnips; vegetable greens like dandelion and beet greens; cruciferous vegetables like cabbage and cauliflower; corn; both green and string beans; pumpkin; kale; okra; beets; garlic; onions and peas. Cabbage, onions, parsley, tomatoes and celery have a higher negative calorie ratio when they are eaten raw, while vegetables like broccoli, spinach, mushrooms, cauliflower, chard and asparagus are better consumed after being cooked.
Common high-grade calorie-burning fruits include pears, strawberries, raspberries, cantaloupe, plums, oranges, grapefruit, blackberries, blueberries, watermelon, lemons, limes and pineapple. Fruits such as apples, cranberries, tangerines, nectarines, grapes, apricots, peaches, cherries, raspberries, pomegranates, papaya, mangoes, honeydew melon, kumquats and tomatoes are considered to be low-grade catabolic foods. HealthRecipes.com reports that all fruits have a higher negative calorie-burning ratio when they are eaten raw.
A variety of fish and shellfish qualify as negative calorie-burning foods. The fish include tuna, flounder, sea bass, trout, buffalo fish and cod, while the shellfish are items such as lobster, crab, clams, mussels, crayfish, oysters, abalone, prawns and shrimp. Frog legs are also believed to be a calorie-burning food.