More like 3.5 stars. This book is marketed a bit like it holds answers to the ever-captivating question of how to be thin, but it is not about that at all. Mann, a psychologist who studies eating and self-control, spends the first part of the book discussing the research on diets and weight loss and how unsuccessful they are by most people's standards. I've been learning a lot lately about research methods and statistics for social science and this was all pretty intriguing. Later, she goes on to talk about workable strategies to happily live at the low end of one's "set weight" and about healthy thinking when it comes to food and weight. Some recent experiments have brought the entire subfield of ego depletion and self control under question, and I'm not sure how much that effects Mann's work or conclusions here, but I liked a lot of this book and her ideas.