The various steps involved in nutrition are as follows:
1. Ingestion: It is the introduction of food into mouth, i.e. intake of food (eating) inside the body.
2. Digestion: The process during which the complex, non-diffusible and nonabsorbable food substances are converted into simple, diffusible and absorbable substances by the action of enzymes is called digestion.
3. Absorption: The process of diffusion of digested food into blood and lymph is called absorption.
4. Assimilation: The process by which protoplasm is synthesized into each cell of the body by utilizing simple food substances are called assimilation.
5. Egestion: The elimination of undigested food from the body is called egestion.
