availability of reduced-calorie and reduced-fat foods, and the broad publicity about the obesity problem, Americäs waistline continues to expand. It will take more than food pyramid images or a new nutritional guideline to stem obesity¿s escalation. Albert Einstein once observed that the significant problems we face cannot be solved at the same level of thinking we were at when we created them, and that we would have to shift to a new level, a deeper level of thinking,tosolvethem. Thisbookarguesfor,andpresents,adifferent perspective for thinking about and addressing the obesity problem: a systems thinking perspective. While already commonplace in engineering and in business, the use of systems thinking in personal health is less widely adopted. Yet this is precisely the setting where complexities are most problematicandwherethestakesarehighest.