Measuring digestion

摘要

Eating food is the mechanism by which humans and animals obtain energy for maintaining the body's functions and to build and replace tissues. Protein, carbohydrates, oil and water are the major components of foods .The gastrointestinal tract, i.e., the mouth, stomach, small intestines and large intestines, digests and ferments thesecompounds to produce amino acids, simple sugars and free fatty acids that pass through the walls of the small intestines into the blood stream.