A readable historical review of how American society has come to admire, even revere thin women--an account that tends toward hyperbole and throws a lot of good out with the bad. Seid, a historian, feels strongly that we are way off track: ""We have been victims, not of a conspiracy, but of a confluence of developments that created a taste for shrunken, fat-free bodies, and that unleashed a war on one of humanity's most basic needs and delights: food."" What we must do, she argues, is work ""our way out of this web of cultural myths and prejudices."" So saying, Seid sets about explaining how we arrived where we are. Defining the present, she attacks the ""New American Creed"": ""I Watch My Weight, Eat Right, and Exercise""--an example, she says, of ""how distorted our values and our beliefs about the body have become."" Seid traces the evolution of this creed from antiquity through to the turn of the century, when thin began to become a preference. By the 1950's, the ""War on Fat"" had begun; in the 1960's, this prejudice became myth, which then became obsession in the 1970's. We are now beyond obsession into a new religion, she thinks. Seid has sometimes mushy studies to back her up (references are cited, but ""On any day, 25 percent of us are on diets, with another 50 percent just finishing, breaking, or resolving to start one"" is a bit much); and she does dismiss a lot of what are legitimate public-health improvements along the way. She has a point about priorities, however: ""Our bodies, our fitness, and our food should not be our paramount concern. They have nothing to do with ethics, or relationships, or community involvements, or with the human soul or spirit."" A passionate argument, but Seid may have it backward. Is our major problem this ""obsession,"" which has appeared as a result of the other developments she cites? Or is one of these other developments--political, moral, whatever--of primary concern, and our obsession for thinness just its byproduct?