One of the best ways you can diffuse your daughters emotional outbursts is to stay calm yourself. I hear from so many parents, “All I said was…and she freaked out! I feel like I am making things worse.”
Your daughter has a voice inside her mind that is abusive and controlling. When you ask her to eat more food or try to talk to her about purging, its like a land mine goes off in her mind. The eating disorder voice is reacting to you, not your daughter. When you realize this it will help you be more objective and not react as emotionally to her.
She does not yet know that this is the eating disorder voice or even if this concept has been explained to her, she cannot yet accept it. So when you make a simple request and suggest she put butter on her toast, it becomes World War III. The eating disorder demands she not allow any fat in her diet so the more upset she gets the less likely you are to push.
The reality is to a certain degree it is effective to engage you in this kind of battle. She knows you cannot force her to eat and so does the eating disorder. Your goal is to not allow her to upset you, but just respond calmly.
Your challenge is to not internalize the things she is saying to you. When she says, “I hate you!” or threatens to eat less or run away, your response can be, “I know you are upset right now, just do the best you can.” Then move on with family conversation or try to distract her by changing the subject.