I think you should focus on Americans, and possibly only on American women. If you say "Everywhere one looks today," you can't claim to be looking all over the world or even all over America. And you can see a lot of women who appear to have eating disorders (especially eating too much), but you can't claim to see that "our culture places a very high value on women being thin."
I think your best opening is in the second sentence. You could say: "An estimated seven million American women have eating disorders of one kind or another and for various reasons. Some eating disorders are caused by stress and are tied into depression and anger resulting from the pressures of modern living. Our culture places a high value on women being thin, often leading to bulemia and anorexia. Many eating disorders stem from problems with women's self-images caused by the popular media. These problems continue to grow and can only be solved through research, educatioin, and legislation."
That last sentence is just a suggestion. I don't know what you intend to say in your paper, but it seems to me that in your conclusion you need to talk about what can be done, what is being done, what should be done to help. If that is too difficult, you might talk about some clinic where they specialize in treating women (or just young girls) with eating disorders. The implication might be that more such clinics would be helpful in coping with this growing national crisis. If you can identify such a clinic, you could probably get a lot of printed information from them by requesting it via e-mail.
I think it is a good idea to discuss the various kinds of eating disorders and the causes in the middle part of your paper. I think you should stick with women, because men's eating disorders may be a whole different issue and just complicate your paper.
In any essay you are trying to sell something. What is it you are trying to sell in this one?