Negative calorie foods are foods, which use more calories to digest than the calories food actually contains. Calories from these foods are much harder for the body to use. In other words, the body has to work hard in order to extract calories from these foods.

The Theory Behind the "Negative Calorie Effect"

All foods have a nutrient (carbohydrate, fat, protein), caloric (calories) and vitamin & mineral content. Vitamins stimulate living tissues to produce enzymes that breakdown the caloric nutrients of that food. 

Foods with negative calorie contain sufficient vitamins & minerals that produce enzymes in quantities sufficient to break down not only its own calories, but additional calories present in digestion as well. This is called "negative calorie effect".

What Foods Have Been Designated as Having “Negative Calories”?

• Vegetables: Asparagus, Beans, Broccoli, Cabbage, Chicory, Carrot, Cauliflower, Celery, Hot Chili, Cucumber, Garlic, Green Lettuce, Leeks, Onion, Radish, Spinach, Tomatoes, Turnip, Watercress, Zucchini

• Fruits: Apple, Blackberries, Blueberries, Cantaloupe, Clementines, Cranberry, Grapefruit, Guava, Honeydew, Lemon/Lime, Mango, Orange, Papaya, Peaches, Pineapple, Raspberry, Rhubarb, Strawberry, Tomato, Tangerine,  Watermelon