Celery has a low calorie and is therefore popular with dieters. However, if you think that the body needs more calories to digest celery than the celery, it is wrong. Celery is a hard, high-water, high-fiber food with only about 10 calories per whole celery.
But according to the dietitian, the calories consumed by the human body to chew, digest and absorb a small amount of celery add up to less than one-fifth of the 10 calories.
In fact, a study of the calories burned by chewing gum estimates that you have to chew for an hour before you can consume the heat of a celery.