Term for someone who calls herself negative things that are not true

Question

What is the correct term for someone who usually says negative things about herself (that she is fat,ugly or dumb) even though she knows that she is not?

Answer 1

The act is called self-deprecation, and so one could conclude that a person who does this is a self-deprecator (the term does not appear in most dictionaries but is easily understood and has been used before).