What do we call organisms that must consume food to obtain energy?

Organisms that must consume food to obtain energy are classified as heterotrophs. This term specifically refers to organisms that cannot produce their own food and rely on consuming other living things, such as plants or animals, to meet their energy requirements. Heterotrophs encompass a variety of organisms, including herbivores, carnivores, and omnivores.

In contrast, producers and autotrophs are terms associated with organisms, like plants, that can produce their own food through processes such as photosynthesis. Meanwhile, while all heterotrophs can be considered consumers in various ecological contexts, the term "consumer" is broader and may also include organisms that have specific roles in food webs, such as scavengers and decomposers. Therefore, the classification of heterotrophs is most precise in the context of organisms that directly need to consume food for energy.