The key difference between absorptive and postabsorptive state is that absorptive state is the state that digests foods and absorbs nutrients into our bloodstream while the postabsorptive state is the state in which the nutrient absorption does not occur, and the body relies on the energy reserves for energy.
Cells produce energy from glucose, lipids and amino acids. They store produced energy as fats, glycogen and proteins. During energy metabolism, chemical changes take place to make the energy available for use. There are three phases of energy metabolism. These three phases are the cephalic phase, absorptive phase and fasting phase or postabsorptive state. Therefore, our body undergoes absorptive and postabsorptive states throughout the day. The absorptive state takes place immediately after each meal while the postabsorptive phase takes places when the GI tract is empty and after the complete absorption of nutrients.
