What calories physically are, and how things like water and celery have none whatsoever?

Question

What calories physically are, and how things like water and celery have none whatsoever?

In: Biology

Answer 1

Calorie is a unit of energy equal to the amount of heat needed to raise the temperature of one gram of water by one degree Celsius. Celery has negative calories because your body burns more calories processing the celery than the celery itself contains.