The human body breaks down food for fuel using the digestive system. After food is swallowed, it passes through the esophagus and into the stomach. Here, strong acids break down food. Next, food passes into the small intestine. While in the small intestine, chemicals from the liver and other organs mix with the food. After the food is digested, nutrients are absorbed into the blood through the small intestine’s wall. Finally, solid waste is passed out of the body.