There is no research evidence to show that negative calorie foods exist. However, there are plenty of nutritious, low calorie foods, such as eggs, white fish, fruits, and vegetables.
Calories are the measure of energy an item of food provides.
When a person exercises, the body uses calories that a person has taken in through their diet as fuel. The body also uses calories to carry out essential functions, such as digestion, pumping blood, and breathing.
When a person consumes more calories than they use through physical activity or normal body functions, the body stores the calories as fat.