Negative calorie food refers to those items that consume more energy during their digestion, in comparison to the amount of energy they gives to the body. We can say that the calorie cost of digesting the food would be greater than its energy content.

These foods are typically high in fibre and have a low glycaemic index. Calories are an important component of food and everything we eat has calories. Calories are of two types. One is empty calories which don't have much nutritive value but just has calories and promotes weight gain. Foods with high fibre and water content usually have fewer calories and we need more energy to digest them, these are called negative calorie foods. These foods help to lose weight as they are not only low in calories but also help to burn out more calories than others. Most negative calorie foods are plant-based.