I think I might be UR, but I suffered from bulimia in my teens and I'm hyperaware of weight issues and EDs.
My 6 year old SIL is fairly enchanted by her teacher. She's mentioned a few times now that she only has yoghurt for lunch. I said that I'm sure she has something else too, but she insists that Miss X says she only eats yoghurt because she is always on a diet. Would you worry about that (both about Miss X's health and about the influence on the children)?