If you grew up in the '90s, you remember the Food Pyramid. It's now outdated, but why hasn't the USDA provided better health ...

The traditional food guide pyramid, adorned with bread and cereal packages, was phased out in 2005 after decades of prominence. Newer pyramids feature vertical lines and variable designs based on age.

In biology the relationship of what eats what and how energy passes through an ecosystem is called a food chain. Pyramids can help give us an overall picture of a particular food chain.