Sense of Smell and Survival

A genetically programmed survival mechanism exists that has anything smelling offensive probably being harmful. A taste defense also exists to protect us from harmful foods/substances (unless cynically masked by the use of salt). The use of salt is one way to make fat taste palatable.

In an opposite sense, out taste provides us with essential amino acids in food, though we are unaware of selection by taste. Like beans-on-toast: each component is a source of a different amino acid. The combination is a good one.