When doctors urge overweight kids to pick up more activities,reading probably isn't what they have in mind.    Yet a new study by fatness researchers at Duke University finds that the simple act of reading--depending on the choice of material--can cause weight loss in teenage girls. The study's experimental group included 31 fat girls aged 9 to 13,who took part in the Healthy Lifestyles Program at Duke Children's Hospital. The girls read a novel called Lake Rescue,whose protagonist   is an overweight teenager who struggles with low selfesteem,feelings of loneliness and teasing because of her size. A group of 33 girls read a different book called Charlotte in Paris,which did not have an overweight character,and another group of 17 girls read neither book. At the end of the sixmonth experiment,all the girls who read books had lost weight,but the girls who read Lake Rescue lost more. They lowered their body mass index (BMI) by 0.71,compared with 0.33 in the Charlotte group,an average 0.05 increase among the nonreaders. The idea behind the study,says Dr Sarah Armstrong,director of Healthy Lifestyles,was to find a way to encourage the girls without adopting the restrictive and often authoritative voice of so many other nutrition and diet programs. Lake Rescue was the perfect instrument,says Armstrong;it presents a likable character to whom the girls could relate and whom they could learn from. As the book progresses,its protagonist learns to make healthier lifestyle choices and finds an adviser to help keep her on track. Armstrong says," _ learns that she can become healthier,and the 'I can do it' feeling resonates   with the teenage girls." What's the main idea of the passage?
There are different ways to help overweight kids lose weight. Lifestyle is important for kids. Lake Rescue is the perfect weightlosing instrument. Reading can help kids lose weight.