I wonder if your daughter is a closet eater. My cousin's son is like this and to him eating is as private as having sex is to some people. He does not only not want his parents to know he eats, but he does not even want them to see him getting food. He's gotten better with the getting food part. But it's been years since anyone has seen him eat. His private eating places are his room and the bathroom. He hides the plates under his bed, in closets and various other places. So you might want to ensure your daughter has the ability to sneak healthy food into her secret eating places without fear of being caught. If she is fearful of being caught, she may decide to either not eat or steal food from some other source. Then every so often search for the dishes. I suspect she may be extremely private about almost anything she is doing right now. The lying goes along with this.
About one out of four people in my family have sleep issues. I think it may be Delayed Sleep Phase Syndrom, but nobody has ever been assessed. It is most common in people with Norwegian ancestry, so this fits well with my family. It is not only the sleep phase which is off, but the metabolism also is shifted.
Neither of these may be your daughter's problems, but as so few people have heard of these before, I figured I would mention them. These rare conditions are often unknown to most of the experts. I would not be surprised if the closet eating may be a possibility however.
