How to make my daughter eat food?

Firstly, lots of support for you. As it seems by your query that your girl is in her teen years when they are most concerned about their looks and their body image. When they are exploring more and more about everything but still they are innocent. Further, 'be waist 22' shows that she is influenced by media. However, according to psychology, there is a tendency of resisting in human beings. We don't like things that are forced to us. Similarly, when someone is resisting us from doing something then, there is an urge of doing that same thing. Hence, if you are trying to be an "elder" with her who is resisting her then, she might become rebellious. On the other hand, if you will try to become a friend of her and let her know your point of view too. Then, the issue might solve. Further, you can make her realize that she is healthy and looks good as she is now. You can also consult a paediatrician if needed.