The food chain is a hierarchical system of consumption where each level depends on the level below it, used metaphorically to describe social systems where power determines who consumes whom.
The food chain describes a natural system of consumption and dependency. Each organism occupies a position that determines what it can eat and what eats it. The position is not chosen but determined by capacity, opportunity, and the existing structure of the chain.
Applied to social and economic systems, the food chain describes the hierarchy of extraction. Those at the top consume the labour, resources, and attention of those below. Those in the middle consume what they can access while being consumed by those above. Those at the bottom are consumed by everyone above them.
The metaphor is structural, not moral. It describes how systems of power organise consumption, not whether this organisation is just. The law of the jungle is the food chain without constraint: when just systems fail to regulate consumption, the strong consume the weak according to their position in the hierarchy.