it has been said that your taste buds actually do change every 7 years. I was trying to find a good link on the information but all I come up with is questionable resources like wiki, ask, chacha and yahooanswers. None of which I would rely on for serious answers. So if you need real information I can keep looking but I know I've heard that many times, that this is the case.

I don't know if they change from week to week, I doubt that but what I think may be happening is that none of our senses are in a bubble, isolated from all the other things within us, your mood, your thinking the physical place you might be in, (environment) I believe will affect your taste and what you crave or loathe. I go on a binge for certain foods I crave for awhile but then another week I might absolutely not want it but I think it's all those factors I mentioned in addition to the fact that I obsessed over that food for awhile and my craving petered out.