Yes I did take some mood stabilizers in the past that caused weight loss (what that term means, the term anoxeria nervosa is what is used to describe the psychiatric disability people might be more familiar with). Some medications have that potential more than others but each person responds differently to each medication. If you have had any unexplained weight loss after starting a specific medication or at any time it would be essential to discuss this with your psychiatrist.
Zeldox (Geodone in the US) caused rapid weight lose for me. It was great at first - lost all the ziprexa weight. In the space of a year I was a size 2 and couldn't keep weight on. So we switched to Abilify. I am still slender but not nearly as bad.
Here in UK, they are quite careful with topamax and weight but I have never heard of a moodstabiliser causing anorexia personally.
To be quite honest I generally hear of all the weight gain issues that seem to come hand in hand with most psychiatric medications.
I wonder,could it be that if someone was predisposed to anorexia, if that could be a factor?!?