How digestion works: what happens to food after you eat it

The lunch in your stomach is not inside your body yet. It gets in only after enzymes cut it into tiny pieces. In 1825, a doctor watched this happen through a hole in a man's side. Follow one meal through your stomach and small intestine into your blood. Then see what insulin does with the sugar, why your body keeps energy as glycogen and as fat, why a soda fills you less than a bowl of beans, and what your gut bacteria eat.