QUOTE : Simple carbohydrates such as sponge cake, rice, or pasta make it through to the small intestine pretty quickly. There, they are digested and rapidly cause an increase in the levels of sugar in our blood. The doorman detains proteins and fats in the stomach for considerably longer. A piece of steak may easily be churned about for six hours before all of it has disappeared into the small intestine. This explains why we often fancy a sweet dessert after eating meat or fatty, fried foods. Our blood sugar levels are impatient and want to rise quickly, and dessert provides a quick blood sugar fix. Meals rich in carbohydrates may perk us up more quickly, but they do not keep us feeling full for as long as meaty or fatty meals. Small Intestine When the mini-morsels reach the small intestine, the real process of digestion begins. As it passes through this tube, the motley cake mush will almost completely disappear into its walls—a bit like Harry Potter on Platform 9¾. The small intestine pluckily pounces on the piece of cake. It squeezes it, hashes it up from all sides, wiggles its villi in what we might now call the cake chyme, and when it is thoroughly mixed, moves it on down the digestive line. Under the microscope we can see that even the microvilli help it along! They move up and down like tiny trampling feet.