Did you know that your digestive system starts working even before you take your first bite of food? The sight and smell of the food makes special glands in your mouth produce saliva or spit.
* An average adult needs between 1,300 and 1,600 calories a day: growing kids ages 7 to 10 need an average of 2,400 . Boys ages 11 to 14 need 2,700 and girls that age need 2,200.
* A meal takes between 12 to 15 hours to go through the whole digestive system.
