After all the discussion, on the day that I went to pick up N from school and take him to wrestling, he informed me that he didn't really want to wrestle. I pulled the car over and we had a long conversation about it. In the end, he said, it was about having a sport - not that he necessarily wanted to do wrestling.
I admit that I was relieved. Though I wanted to be supportive and I wanted to believe that he was well on his way to recovery from the anorexia, I still had warning bells sounding in my head. Thankfully, we didn't have to find out with such an anorexia-prone sport like wrestling. He's looking forward to possibly doing shot-put in the spring. That I think he can manage much better.
(Added 2/18/2011) - We continue to be grateful for N's decision not to do wrestling. He sat one day after school and described the constant conversations about weight and calories by his buddies that are still in wrestling. His friends are skipping meals in order to make weight. Regardless of the changes that wrestling has made to combat this problem, the reality is that the obsession with weight is still there.