Well, we navigated trek successfully. I loved that I was able to be there and offer support if needed. The only time I was concerned was during an activity where rather than feed the youth lunch, they were given a 1/4 cup of flour (which is all that the handcart companies of 1856 had to eat before the rescue wagons arrived). The accompanying doctor checked in with me right before the activity. I was able to reassure him that N had been told about the activity (and that they would get a normal lunch afterwards). It wasn't even an issue.
There aren't too many days until school starts (where did the summer go?). I've already contacted N's physical education teacher and have determined that there shouldn't be any problems there. I haven't heard from his health teacher yet - and I've both called and emailed. I heard rumors that one of the health teachers had previously suffered from an eating disorder. Once again there is a unit on eating disorders. We'll likely ask for N to be excused. At this point I'm just worried that she hasn't contacted me - that doesn't exactly bode well for communications in the future.
Lastly, N has started exercising with a friend. They are weight-lifting and/or running daily, all of which are fine if done with compensating calories and without obsession. We're watching carefully. So far, so good.