food pyramid

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A graphic representation of the structure of a food chain, depicted as a pyramid having a broad base formed by producers and tapering to a point formed by end consumers. Between successive levels, total biomass decreases as energy is lost from the system.
• noun A diagram representing the optimal number of servings to be eaten each day from each of the basic food groups.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A pyramid shaped diagram in layers, where each layer represents a group of animals that feeds on the layer below.
• noun US Any pyramidal diagram giving advice on how to eat healthily, particularly those widely publicized by the united states government.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (ecology) a hierarchy of food chains with the principal predator at the top; each level preys on the level below