dr. zucker makes shopping a game, picking out hard foods in addition to easy ones. they're working up to erin's goal, that slice of pizza. >> can you describe it? >> it's a triangle. >> oh, nice. >> reporter: remember, the only cheese she's eaten up to now is processed american cheese. the pizza proves to be just a step too far. but it's only been five days of treatment. they've got a lifetime to go and a lot of foods to try. this is vicki mabrey for "nightline" in durham, north carolina. >> situation is tough for the whole family. >>> when we come back, hilary swank and the real-life heroine she portrays in her new movie. on our car insurance. great! at progressive, you can compare rates side by side, so you get the same coverage, often for less. wow! that is huge! [ disco playing ] and this is to remind you that you could save hundreds! yeah, that'll certainly stick with me. we'll take it. go, big money! i mean, go. it's your break, honey. same coverage, more savings. now, that's progressive. call or click today. you can take the heat. 'til it turns into heartburn

dr. nancy zucker. >> so it's not just like a simple fix like eat this, right?'ve tried that. we're not just talking about i don't like my broccoli and i'm not going to eat my peas. >> reporter: dr. zucker runs the center for eating disorders at duke where they're just starting to study food neophobia. >> can you take me inside the mind of a picky eater? >> my best guess would be where we would look at a plate of food and say, like, oh, look at this lovely food adventure. they would look at a plate of food and be like, danger, danger. >> reporter: the first few days focus on the psychology behind erin's eating. they also evaluate her sense of smell and count her taste buds to see if she's hypersensitive. how do you lead them from eating five foods to eating a range of foods? >> when kids are not eating properly, it's terrifying for parents. and so what ends up happening inevitably is meals become stressful. >> one, two, three. >> all the work with erin is retraining her experience with food to relax her body and her mind. >> reporter: erin has a goal for the wee

dr. zucker's help, erin begins to alter her some of her eating habits.ibe her food visually. she's also encouraged to play with her food. and the whole family is sent to a drumming and dance class to teach them to relax. >> we're looking for three foods. >> reporter: at week's end, it's time for a trip to the local whole foods grocery store. dr. zucker makes shopping a game, picking out hard foods in addition to easy ones. they're working up to erin's goal, that slice of pizza. >> can you describe it? >> it's a triangle. >> oh, nice. >> reporter: remember, the only cheese she's eaten up to now is processed american cheese. the pizza proves to be just a step too far. but it's only been five days of treatment. they've got a lifetime to go, and a lot of foods to try. this i mabn du abotat it's a scary condition. >> that's heartbreaking. if you are unsure if you child might have this disorder, they say usually if they present symptoms like disliking the food's taste or smell, danger in eating something different or disgust, just open disgust at seeing someth