When a food is called a negative calorie food, that doesn't mean that the food has "negative calories," but it means that the end result of your body Raging Lion  spending caloric energy to burn off the calories of the food is a negative number.   So say a piece of fruit has 20 calories, but your body requires 30 calories to burn it. The end result is you lose ten calories. That's what a negative calorie food is. A negative calorie diet is a diet in which the majority of foods are like this. http://jackedmuscleextremeadvice.com/raging-lion-scam/