Marisa's Diet

I am torn over Marisa's eating habits. On the one hand I really hate that Marisa isn't happy with her body because she is "chubby." Sometimes I feel that these types of characters only perpetuate the media frenzy of skinny being the only beautiful. At the beginning of chapter 7 Marisa even describes how hungry she is and how she feels weak from not eating!!! On the other hand there are many obese students sitting in our schools. In the novel Soto talks about the healthy foods that Marisa is eating instead of the junk food. Encouraging students better couldn't hurt. So I am not sure where I stand with the "food issues" in this novel. Any thoughts?