Children's book encourages little girls to be skinny

A new children's book, Maggie Goes On a Diet, is making headlines. It is about a chubby girl who stands in front of the mirror holding up a too-small pink dress and sees a different version of herself. Her mirror image is, of course....thin. "This book is about a 14 year old girl who goes on a diet and is transformed from being extremely overweight and insecure to a normal sized girl who becomes the school soccer star. Through time, exercise and hard work, Maggie becomes more and more confident and develops a positive self image." - Amazon description

Is the only way to be better, to be skinny? Are young girls supposed to be taught that being chubby is an awful thing? If it is unhealthy, yes of course, but this book is just preposterous!