I'm an adult psychiatrist. I believe you'll also hear testimony from some of the child psychiatric experts in this area.
One who I believe is going to be invited is Dr. Leora Pinhas from Toronto, who sees patients as young as seven and eight, with what she is pretty convinced is full syndrome anorexia nervosa. She tells me that she thinks the age of onset is getting earlier and earlier. When she started in this 10 or 15 years ago, it would have been unusual for her to see a child before the age of puberty, and at this point, it's relatively common.