Here is a list of 15 Negative calorie foods. What is a negative calorie food? Something that takes more energy to digest than the food contains itself.

  1. Celery
  2. Oranges
  3. Strawberries
  4. Tangerines
  5. Grapefruit
  6. Carrots
  7. Apricots
  8. Lettuce
  9. Tomatoes
  10. Cucumbers
  11. Watermelon
  12. Cauliflower
  13. Apples
  14. Hot Chili Peppers
  15. Zucchini

To find out more info about these I suggest reading Bootstrapper