Your breaks down foods and liquids into their chemical components carbohydrates, fats, proteins, and the like that the body can absorb as nutrients and use for energy or to build or repair cells. Food's journey through the digestive system begins in the mouth. It passes down the esophagus and into the stomach, where digestion begins. Next stop: the small intestine, which in the average person is more than 20 feet long. The small intestine further breaks down food, absorbs nutrients, and sends them into the bloodstream.