Nutrition can be defined as the process by means of which living organisms obtain and process parts of their external environment for the continued functioning of their internal chemical processes. The need to eat food is one of the characteristics that defines a living organism as an animal.  

Eating food is essential for the health, reproduction, and psychological needs of animals.  

In the wild, animals spend a lot of time searching for food. When they have found it they have various behaviours to obtain it and then handle or process it before eating it. If in the zoo, food is presented to the animal all at one time and in a form ready to eat, the animal has little opportunity to perform its normal wild behaviour. Keepers must think about how food should be presented to the animal. 

Is it natural? Does it make the animal think about how to get food? 

Observations on feeding activities are a good example of the interlinking of research, husbandry, and conservation activities of zoo staff for visitors. 

 It has been estimated that before 1970, 60-70% of animals dying in zoos did so because of poor husbandry and management, with approximately 25% dying because of nutritional issues. The results of studies in zoos and of animals natural diets have led to the development of better nutrition for captive animals.