Zero Calorie or Negative Calorie foods are those that burn more calories than they contain. They are foods with 25-60 calories per REASONABLE serving. The word reasonable is important , just because a particular food item has almost no calories does not mean that we can consume just any amount of it. The calories keep on adding , REMEMBER THAT. Vegetables like cucumber, leafy greens, red bell pepper,asparagus, mushroom,brocolli , cauliflower,beetroot,tomato are great options . Fruits like water melon, citrus fruits,strawberry, blueberry, apricot are variety to choose from. Include these food in your diet and see the difference.