One of the nutrition experts that I highly recommend is Anne Fletcher, RD. She is the award winning author of Thin for Life, a book which describes the real life strategies that people who have been successful at losing weight use to make sure the weight stays off for good.
Her newest book, Weight Loss Confidential, has a similar theme, although it deals strictly with teens. A companion journal to the book is available, too. Click on the links below to view a couple of short videos in which Anne and a number of her teen clients discuss their weight loss journeys: