FAST food definately put a lot of importance in taste. Double-blind test testing of hundreds of variations in flavoring, scent enhancers, etc. goes on constantly in the corporat "food labs" of these places.

Do you have any idea how many different chemicals are in your average value meal? I'm not talking about the stuff that was already in the potatoe, cow or wheat field before they were converted into food. I mean factory-made stuff that often doesn't even exist in nature. (Supposedly a single drop of one brand of concentrated "green pepper" flavoring could flavor a swimming-pool size vat of pizza sauce.)

Anyhow, making you want to come back again and again has a lot more to do with corporate fast-food decisions than whether or not the stuff will kill you over time.