In this post (http://nourishingmyson.blogspot.com/2008/12/fears-of-future.html), I described some of my concerns for N's future. I've done a little research since then. Apparently, the military would reject N because of his eating disorder. Eating disorders are included in the "unwaiverable medical conditions," but they are only documented if they occur after the applicant is 12 years old. I wondered about civilian positions, but wasn't able to find any additional information. This makes total sense to me. In tough conditions, especially those with high calorie expense and low calorie intake, someone potentially relapsing into anorexia could compromise a mission.
As far as him serving a mission for The Church of Jesus Christ of Latter-Day Saints, they do ask about eating disorders on the application. His Bishop (like a Pastor) would attach a letter explaining the terms and severity of the anorexia. Then depending upon his current health, he would be assigned. I hope that he would be asked to serve in a country with good food. :o) I really think he could contribute positively on a mission as long as he didn't have to walk everywhere and struggle to find good food.