Putting the pressure on girls that not only must they lose weight, but also they must become extremely popular super-heroines (e.g., soccer stars)after they slim down is the wrong approach. Their own health and well-being should be the ONLY issue; happiness, popularity, success, and any other issues are NOT required. It's like those stories of dogs who receive the love and appreciation they deserve and need only after they become heroes or heroines by rescuing a child from a fire or some such thing, rather than for being the loving and protective companions that they innately are.
It is true that overweight children of both genders suffer from social abuse and rejection, but so do overly thin ones, kids with eyeglasses, gay kids, children from any kind of unusual families, different skin colors, and any number of other meaningless and cruel reasons. Whether they can change any of these or not, there will always be "stars," ordinary people, and "losers." As almost everyone knows, even slender people can be lacking in self-confidence and social comfort.
Losing weight is seldom the answer to the array of social and family issues that this book claims that it is; lovely for the girl if she always wanted to succeed in something that was helped by her losing weight -- but have you noticed how it is always portrayed as "losing weight," and never "gaining health" (or "losing virginity" & not "gaining sexuality"?
Every woman who has been on a diet, or several, knows that "diets" do not work in the long run; only lifestyle changes and wholesome eating patterns, not rigid diets, do. In fact, most mainstream "diets" include wheat and dairy products, which are extremely harmful to many of us.
The only redeeming quality of this book is that is does show that a girl can exercise some personal power over her own life, and that, I agree, is good.