Not sure if you are in the same boat as me for treatments. I'm getting chemo and radiation concurrently. The radiation definitely reduced my ability to taste. I thought it was also to blame for foods tasting terrible. I found out, however, that the chemo was the culprit for making foods taste bad. It was week 4 for me also, which happened to be the week after my second chemo treatment. Later that week, after flushing more of the chemo out of my system, food started just having the reduced flavor again. Hope it turns out to be the case for you too. I know I was devastated when butterscotch pudding, one of the few foods I loved that I could still eat, tasted terrible.