How Does Digestion Work and How Can I Improve Mine? (Animated graphics)

The food you eat contains the nutrients that serve as building blocks, and provide energy and nourishment throughout your body. In food, nutrients are contained in large molecules that are chemically and physically bound together. Digestion is the process of breaking down these tightly bound molecules into individual nutrients that can be taken into your body and used to support its functions. Simply defined, digestion is cutting things down to a size in which they can be absorbed into your body.

Digestion occurs in the gastrointestinal tract—the 20 to 30 foot long tube extending from your mouth to your anus. Whatever you eat flows through this system, but until it is absorbed through the intestinal tract, the nutrients in food are physically outside of your body. This is because the gastrointestinal tract functions like an internal skin and provides a barrier between whatever you ingest from the outside (external) world and your internal bloodstream and cells. Part of the digestion process, then, is the selective transport of nutrients through the cell wall that lines your intestinal tract. Once transported across the intestinal barrier to the inside of your body, these nutrients can enter your bloodstream and circulate to all of your tissues to maintain organ function, support your need for energy, and provide for growth and repair of new cells and tissues.

While digestion can be simply defined, its mechanics are quite complex. This is because your food contains so many different sizes, shapes, and types of individual molecules, all tightly entwined, and because each of these types of molecules is chemically distinct. Digestion uses both mechanical processes, such as chewing and grinding, which help separate the different types of molecules, as well as chemical processes, in the form of enzymes that can cut the bonds within the molecules, to release small nutrients into your system. An analogy is two or more necklace chains of different types twisted, knotted, and interlocked together. Digestion would be the process of untwisting and separating the chains, usually requiring cutting them in a couple of places, and then pulling them apart and further cutting each of them into many smaller pieces, so they can become building blocks for other necklace chains.