The explanation for this surprising effect has to do with how our digestive system works. In order to visualize it, think of your stomach as a sink and your small intestine as the pipe below it. Anything you eat lands in your sink, then flows through to your pipe, where it is broken down and absorbed into your bloodstream. Every minute, on average, about three calories’ worth of food trickles through from sink to pipe. (This process is called gastric emptying.)
