Holozoic nutrition is a type of heterotrophic nutrition. Autotrophic nutrition is where an organism can produce its own food, like plants with photosynthesis. Heterotrophic nutrition is where an organism cannot make its own food and must intake external food from other sources.
The word holozoic derives from the Greek words holos (meaning "whole") and zoikos (meaning "of animals"). It is the basic food intake, processing, and absorption model that humans and most animals utilize for nutrition. It involves five basic steps in humans:
1. Whole foods enter the body through the mouth.
2. The food particles are broken down through mastication (chewing) and saliva enzymes, followed by the food molecules being broken down chemically in the stomach via enzymes and acid.
3. The small organic molecules (nutrients) that food is made up of are absorbed into the bloodstream through the intestines.
4. The nutrients are utilized by different parts of the body to perform essential functions.
5. Waste products and unused food particles are removed from the body via elimination (urination and defecation).