The only problem with mushrooms is that they are a fungus and will affect someone who is stalled by a yeast overgrowth. If you are losing, don't worry about it.

Dr. Atkins says its very difficult to lose weight if you have a yeast problem. The most common foods to avoid are (sugars and starches) cheese, nuts, mushrooms, vinegar-containing products and anything else with yeast in it i.e. bread and some vitamins.

I just started a yeast avoidance regime yesterday and dropped three pesky pounds as of this morning. I have been stuck for six weeks. This cannot be coincidence. The food is pretty boring, but it's got to be worth it.