Carb-Digestion begins in your mouth where the process of chewing mechanically breaks food into small pieces. Enzymes in the saliva initiate chemical digestion. When you swallow, partially digested carbs travel down your esophagus to the stomach with little additional digestion. From there, carbohydrates move into the small intestine where enzymes released by the pancreas break them into simple forms to be absorbed into the bloodstream
Lipid-Some digestion occurs in your mouth and the stomach, but most takes place in the small intestine. Bile is produced by your liver, stored and released in your gall bladder and emulsifies fat globules into smaller droplets. This greatly increases the surface area that allows lipase, a fat-digesting pancreatic enzyme, to aid in digestion.
After digestion, these broken-down fat particles called fatty acids combine with cholesterol and bile to move into your cells' mucosa where they are reconverted into large molecules, most passing into vessels -- called lymphatics -- near the intestine. These vessels transport fat to the veins of your chest, and the blood carries fat to be stored in adipose tissue throughout your body.
Protein-Digestion of protein begins in your stomach with the aid of gastric juices. Through the action of a group of potent enzymes from the intestinal lining and the pancreas, digestion continues in the small intestine. From there, amino acids are absorbed into the bloodstream and transported throughout your body.