Actually, the well known "stomach growl" is not a sign of hunger. Our intestines frequently "move", and when they do they make an audible rumbling sound. When a portion of the intestine is empty, the sound in that area is amplified (like an echo). We call that sound a stomach growl.
The human body is equipped with a "fuel gauge" (tells us when we need to eat). However, most "westernized" folks tend to eat out of habit, not hunger. Our bodies are so used to consuming food around certain times that our "hunger meter" tells us we need to eat around those times whether we actually need refueling or not.
