Let's look at how umami explains why pizza is one of the best foods. Umami, which is used as both an adjective and a noun, is a taste sensation produced by naturally occurring glutamate, an amino acid that's often found in meat and some vegetables. Pizza contains a large amount of glutamate.

Pizza toppings are also packed with a compound called glutamate, which can be found in the tomatoes, cheese, pepperoni and sausage. When glutamate hits our tongues, it tells our brains to get excited — and to crave more of it. This compound actually causes our mouths to water in anticipation of the next bite.