The same way all foods are digested. Digestion actually starts in the mouth from chewing and secreting digestive juices that begin to loosen the foods contents before you swallow it. The “mushy” result is swallowed and ends up in the stomach, which is a very acidic environment that helps further loosen the foods ingredients with aid of specific enzymes. Meat/beef requires more acid and leads the body to release specific enzymes (e.g. pepsin) to break it down further to what your body can use such as the amino acids, vitamins and minerals. From the stomach, meat components begin the longer journey into your intestines where another enzyme, trypsin, completes the breakdown of the proteins from meat into amino acids that are now available for absorption into the blood stream and transported to where they are needed. The leaner the beef the faster this process takes place and vice-versa. Fat slows the digestion of all foods but like all foods, beef components enter the blood stream in a few hours and the remainder passes in your subsequent bowel movement with the rest of food stuff your body did not absorb. Don’t buy into the stories about humans taking days to digest beef – WRONG! Humans evolved with a marvelous digestive system that’s built to digest plants, grains and meats. The availability of foods as humans multiplied and migrated led to this wonderful trait.